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The  Burling  Vocational  Series 


LOOSE  LEAF  SHOP  MANUAL 


. 


REPAIR 


BY 


BEVERLY  B.  BURLING,  S.B.,  E.E. 


One  of  a Series  of  Manuals  covering  Trade  Subjects  compiled  especially  for 
Technical  High,  Continuation  and  Trade  Schools. 


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Property  of. 


The  Burling:  Vocational  Series, 
B.  B.  Burling,  Editor. 


LOOSE 

Return  this  book  on  or  before  the 
Latest  Date  stamped  below.  A 
charge  is  made  on  all  overdue 
books.  TT  , T T ., 

U.  of  I.  Library 

DEC  23  194 

1 

BATTERY 

Mar  19  1343 

R 

V 

A Manual  for  Techni 
for  Evening  Cla 
Autc 

BEVERLY 

Industrial  Training  for  Met 
Extension  Depar 
Past  Supervis 

M32 

The  Bruce  Publishing  Company, 
Milwaukee,  Wis. 


LOOSE  LEAF  SHOP  MANUAL 


BATTERY  TESTING  AND 

REPAIR 


A Manual  for  Technical  High  Schools,  Trade  Schools  and 
for  Evening  Classes  in  Applied  Electricity  and 
Automotive  Electricity. 


BY 


BEVERLY  B.  BURLING,  S.B.,  E.E. 

Industrial  Training  for  Men  and  Boys,  Milwaukee  Board  of  Education, 
Extension  Department,  University  of  Wisconsin, 

Past  Supervisor  of  Co-operative  Education. 


The  Bruce  Publishing  Company, 
Milwaukee,  Wis. 


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Loose  Leaf  Shop  Manual 
Burling  Vocational  Series 
Battery  Testing  and  Repair 


BATTERY  TESTING  AND  REPAIR 

TABLE  OF  CONTENTS 


Title 


Preface 

Contents 

Electrical  Symbols 
Standard  Test  Report  Blank  - 

Definitions  of  Terms  Frequently  Used  in  Battery  Work 

A-  1 — Construction  of  the  Storage  Battery. 

A-  2 — The  Conversion  of  Chemical  Into  Electrical 
Energy. 

A-  3 — The  Hydrometer  and  Thermometer. 

A-  4 — The  Electrolyte. 

A-  5 — The  Voltmeter. 

A-  6 — The  Ammeter. 

A-  7 — Polarization  of  Primary  Cells. 

A-  8 — Series  and  Parallel  Combination  of  Cells. 

A-  9 — Charging  Battery  Using  Hydrometer  for  Testing. 
A-10 — Complete  Test  of  Six  Volt  Battery. 

A-ll — Ampere-hour  and  Watt-hour  Capacities. 

A-12 — Storage  Battery  Efficiency. 

A-13 — Curb  Service  Instruction  Sheet. 


A-14 — Battery  Diagnosis  Prior  to  Opening. 

A-1S — The  Cadmium  Test  on  Charge  and  Discharge. 
A-16 — Testing  Battery  Jars. 

A-17 — How  to  Open  a Lead  Storage  Battery. 

A-18 — Winter  Storage. 

A-19- — Minor  Defects  and  Repairs. 

A-20 — Lead  Burning. 

A -21 — Major  Defects  and  Repairs. 

A-22 — Installation  of  New  and  Old  Batteries. 

A-23 — Care  of  a Storage  Battery. 

A-24 — Testing  and  Repair  Equipment. 

A-25 — Electric  Vehicle  Operation. 

A-26 — Charging  Equipment. 


Copyright  1922,  B.  B.  Burling 
Bruce,  Milwaukee,  Publishers 


m \r 

' 

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I 


Loose  Leaf  Shop  Manual 
Burling  Vocational  Series 
Battery  Testing  and  Repair 


H _ 

Hf- 

H M 


SYMBOLS 

Single  Battery  Cell. 

Battery  of  Two  Cells  Connected  in  Multiple  or  Parallel. 


Battery  of  Three  Cells  Connected  in  Series. 


Ammeter. 


Voltmeter. 


Wattmeter. 

Single  Pole  Switch. 


Double  Pole  Switch. 


mrnw  Resistance. 

{ 

AAAA/WVW  Variable  or  Adjustable  Resistance. 

OR  — i Lamp. 


Positive  Terminal  of  Battery. 
Negative  Terminal  of  Battery. 


Armature  and  Brushes  of  Motor  or  Generator. 


Wires  Crossing. 


Wires  Connected. 


Copyright  1922,  B.  B.  Burling 
Bruce,  Milwaukee,  Publishers 


Digitized  by  the  Internet  Archive 
in  2017  with  funding  from 

University  of  IllinoisdWrb&na-Champaign  Alternates 

' 


https://archive.org/details/looseleafshopman00burl_0 


Loose  Leaf  Shop  Manual 
Burling  Vocational  Series 
Battery  Testing  and  Repair 


PREFACE 

The  effort  has  been  throughout  this  work  to  get  away  from  a theoretical  treatment  of  battery  prob- 
lems and  discuss  the  topics  in  a practical  manner.  The  information  given  in  many  cases  does  not 
absolutely  agree  with  any  one  make  of  battery,  but  is  sufficiently  accurate  for  commercial  work. 

The  author’s  broad  experience  as  superintendent,  electro-chemist  and  consulting  engineer  for 
several  of  the  largest  battery  companies  in  the  United  States,  has  been  responsible  for  this  brief  and 
vet  inclusive  treatment  of  the  subject. 

In  handling  the  subject  of  “Battery  Testing  and  Repair,”  the  methods  of  treatment  used  previ- 
ously have  been  greatly  modified.  The  theoretical  work  requisite  for  a clear  understanding  of  the 
test  and  other  allied  information  is  placed  on  the  rear  of  the  test  sheet.  The  practical  test  and  the 
explanatory  material  is  thus  closely  correlated.  This  is  almost  impossible  in  the  average  treatment 
of  shop  or  laboratory  work. 

The  “Loose  Leaf”  method  makes  it  possible  to  use  the  assignments  in  any  order  the  instructor 
may  desire. 

The  lead  battery  is  only  considered  inasmuch  as  the  average  service  station  is  not  equipped  to  re- 
pair the  Edison  battery  economically. 

GENERAL  INSTRUCTIONS  FOR  SHOP  WORK 

The  greatest  benefit  to  be  derived  from  this  course  is  the  ability  to  investigate,  determine  and 
rectify  the  difficulty.  All  commercial  batteries  differ  mostly  in  minor  details.  It  is  important  to 
know  these  details  in  order  to  make  quick  repairs. 

Experience  has  proven  that  the  best  results  can  only  be  obtained  through  individual  effort. 

Note 

(a)  When  assigned  to  a problem,  go  immediately  to  the  station  where  the  work  is  to  be  done. 

(b)  Read  carefully  the  directions  given  on  the  assignment  sheet.  Be  sure  you  understand 
what  the  test  calls  for. 

(c)  Get  whatever  meters,  tools,  wire,  etc.,  are  necessary  from  the  stock  room,  and  examine 
meters  carefully  to  see  that  the  instruments  are  in  good  condition. 

(d)  All  ammeters  should  be  properly  fused. 

(e)  Obtain  all  information  available  on  the  test  being  conducted  and  incorporate  the  same  in 
your  “write  up.” 

(f)  Keep  a record  of  the  time  required  to  perform  each  operation.  This  information  will 
prove  very  valuable  in  estimating  the  cost  of  repairs. 

Instructor’s  Note:  The  instructor  is  expected  to  supplement  this  course  with  lectures,  demonstra- 
tions and  discussions,  on  uses,  characteristics,  advantages,  disadvantages,  chemical  reactions,  etc.,  of 
Plante,  Faure  and  Edison  Batteries. 


Copyright  1922,  B.  B.  Burling 
Bruce,  Milwaukee,  Publishers 


Loose  Leaf  Laboratory  Manual 

REPORT  BLANK  (2) 

Course 


Number: Name  of  Test: 

Date:  ___ ’ Name  of  Student: 

Object  of  Test: 


Apparatus : 


References : 


Diagram  of  Connections  or  “Set-up”: 


i 

i 


i 


Reserve  this  space  for  In- 

structor’s  Check  on  Connec- 

tions. 

Test  Data: 

No. 

1 

2 

3 

4 

5 

6 

7 

8 

9 

10 

11 

12 

13 

14 

Copyright  1922,  B.  B.  Burling 
Bruce,  Milwaukee,  Publishers 


Sample  Calculation: 


Calculated  Data : 


No. 

1 

2 

3 

4 

5 

6 

7 

8 

9 

10 

11 

— 

12 

13 

14 

Theory  and  Detail  of  Test: 


Results  and  Conclusions: 


Reserve  this  space  for  final  check 
of  Instructor. 


Loose  Leaf  Shop  Manual 
Burling  Vocational  Series 
Battery  Testing  and  Repair 


DEFINITIONS  OF  TERMS  FREQUENTLY  USED  IN  BATTERY  WORK 
Acid:  The  solution  used  in  the  battery.  See  Electrolyte. 

Active  Material:  The  peroxide  on  the  positive  plates  and  spongy  lead  on  the  negative  plates. 
Alternating  Current  (a.  c.)  : Electric  current  which  periodically  changes  in  direction.  Cannot  be 
used  in  battery  charging  except  with  a rectifier. 

Ampere  (amp.)  : An  electrical  unit  of  measurement  to  measure  the  rate  of  flow  of  electricity. 
Ampere-hour  (amp.  hr.)  : Product  of  amperes  and  hours,  or  the  unit  used  to  measure  quantity  of 
electricity. 

Battery  (batt.) : Two  or  more  cells  connected  and  used  together.  (Also  used  commercially  when 
referring  to  one  cell.) 

Bridge:  Supporting  ribs  in  the  jar  to  raise  the  plates  above  the  bottom. 

Buckling:  The  warping  of  the  positive  plates. 

Burning:  The  process  of  welding  two  pieces  of  lead  by  melting  them  along  the  line  of  contact  and 
permitting  them  to  run  together. 

Burning  Bar:  The  bar  of  lead  that  is  used  to  fill  in  the  joint  where  two  pieces  of  lead  are  burned 
together. 

Cadmium  (cd.) : A metal  in  the  shape  of  a pencil  used  to  test  condition  of  positive  and  negative 
plates  by  voltmeter  readings  between  said  cd.,  (when  inserted  in  the  electrolyte)  and  the  regular  plates. 
Capacity:  The  Ampere  hour  (amp.  hr.)  rating  of  a battery  depending  on  the  rate  of  discharge. 
Case:  A container  which  holds  cells  of  a battery. 

Cell:  A complete  battery  unit,  consisting  of  plates  assembled  in  one  jar  with  electrolyte  and  cover. 
Cell  Connector:  See  connector. 

Charge:  Passing  direct  current  through  a battery  to  replace  the  chemical  energy  used  on  discharge. 
Charging  Rate:  The  proper  ampere  rate  used  to  charge  a battery. 

Connector:  A means  of  electrically  connecting  cells  together  or  to  the  external  circuit. 

Corrosion:  The  action  of  the  electrolyte  upon  connectors,  terminals,  battery  hold-downs,  or  any 
metal  with  which  it  comes  in  contact. 

Cover:  Cover  to  prevent  slopping  of  electrolyte  and  foreign  matter  entering  the  cell. 

Cycle:  One  charge  and  discharge. 

Density:  Gravity  or  specific  gravity. 

Developing:  Bringing  a new  or  repaired  battery  up  to  its  rated  capacity  by  one  or  more  cycles  of 
charge  and  discharge. 

Diffusion:  The  movement  of  acid  within  the  pores  of  a plate. 

Discharge:  The  flow  of  electric  current  from  a battery  in  opposite  direction  to  flow  on  charge. 
Dry:  Applied  to  a storage  battery  with  semi-solid  electrolyte,  or  to  a battery  with  insufficient 
electrolyte. 

Electrolyte:  Correct  name  for  conducting  fluid  inside  any  cell. 

Element:  The  assembly  of  a pos.  group,  neg.  group  and  separators. 

Equalization:  The  movement  of  acid  in  the  cell  and  in  the  pores  of  the  plates  tending  to  equalize 
the  gravity  throughout  the  cell. 

Equalizing:  Bringing  the  electrolyte  in  all  battery  cells  up  to  the  same  density. 

Evaporation:  The  loss  of  water  from  the  electrolyte  due  to  charging  or  heating. 

Finishing  Rate:  A rate  approximately  one-half  the  charging  rate  used  when  a battery  is  practi- 
cally charged,  or  when  the  charge  is  to  continue  longer  than  the  prescribed  time  for  the  charging  rate. 
Flooding:  Filling  the  cells  to  overflowing  with  either  acid  or  water. 

Forming:  The  electrochemical  process  of  changing  the  “green”  pasted  and  lead  plates  into  active, 
positive,  or  negative  plates. 

Foreign  Substance:  Injurious  materials. 

Freshening  Charge:  A light  charge  given  a battery  after  standing  idle  in  order  to  bring  it  up  to 
“full  charge.” 

Gassing:  The  bubbling  of  hydrogen  and  oxygen  gases  which  rise  to  the  surface  of  the  electrolyte 
when  a battery  is  nearing  “full  charge.” 

Gravity:  A popular  term  for  specific  gravity. 

Green  Plates:  Unformed  plates. 

Grid:  The  metal  frame-work  which  holds  the  active  material. 

Group:  Two  or  more  plates  of  a kind  assembled  as  a unit. 

Hold-Down:  A means  of  holding  separators  in  position  and  preventing  them  from  floating. 

A means  of  holding  a battery  in  position  on  the  car. 

Hydrometer:  An  instrument  for  measuring  the  gravity  of  the  electrolyte. 

Jar:  A container  of  insulating  material  in  which  the  elements  are  placed  after  assembly. 

Lug:  The  projection  from  a plate  to  which  the  connecting  strap  is  burnt. 


Copyright  1922,  B.  B.  Burling 
Bruce,  Milwaukee,  Publishers 


Loose  Leaf  Shop  Manual 
Burling  Vocational  Series 
Battery  Testing  and  Repair 


Mud:  Sediment  in  the  bottom  of  the  jar. 

Ohm:  An  electrical  unit  of  measurement  used  to  measure  the  resistance  of  the  circuit. 

Over-charge:  Charging  a battery  until  gas  is  given  off  at  a low  rate  of  current.  Gas  is  generally  an 
indication  that  the  cells  are  fully  charged  when  the  rate  of  charge  is  low. 

Over-discharge:  Discharging  a cell  below  the  critical  point  of  voltage  depending  upon  the  rate  of 
current  flow. 

Paste:  The  mixture  of  lead  compounds,  etc.,  which  upon  forming  become  the  active  material. 

Plate:  The  properly  formed  pasted  grid.  Positives  are  reddish  brown,  and  negatives  slate  gray. 

Polarity:  The  electrical  position  which  one  part  of  a circuit  has  to  another.  If  the  current  is  flow- 
ing to  it  from  another  part,  it  is  said  to  have  negative  polarity  and  the  other  to  have  positive  polarity. 
The  positive  plate  has  therefore  a positive  polarity. 

Positive:  The  terminal  from  which  the  current  leaves  the  source  of  energy.  Marked  “Pos.” 
or  l+”- 

Post:  The  terminal  of  a cell  to  which  the  external  circuit  or  another  cell  is  connected. 

Potential  Difference : Voltage. 

Rate:  The  time  or  number  of  amperes  for  charge  or  discharge. 

Rib:  (See  Bridge). 

Ribbed:  (See  Separator). 

Reversal  (of  Voltage)  : The  condition  which  occurs  when  a battery  is  over-discharged  or  charged 
in  the  wrong  direction. 

Sealing:  The  fastening  or  enclosing  of  the  battery  with  a compound  which  will  adhere  to  the  cover, 
jar  sides,  and  posts,  and  prevent  leakage  of  electrolyte. 

Sediment:  The  accumulated  particles  of  active  material  in  the  bottom  of  the  cell.  Also  called 
“mud.” 

Sediment  Space:  The  space  between  the  “bridges”  at  the  bottom  of  the  jar. 

Separator:  The  spacer  (wood,  rubber,  etc.)  placed  between  plates  of  opposite  polarity  to  permit 
acid  circulation  but  prevent  contact.  Separators  are  generally  “ribbed,”  “grooved,”  or  “corrugated.” 

Short  Circuit:  (Internal)  The  connection  of  plates  of  opposite  polarity  due  to  broken  separator, 
accumulation  of  sediment,  or  foreign  metallic  substance  within  the  cell. 

(External)  : The  flow  of  electric  current  through  an  unknown  or  uncontrolled  path. 

Specific  Gravity:  The  density  or  weight  of  acid  as  compared  with  a like  amount  of  water. 

Spray:  The  mist  which  arises  when  a battery  is  gassing  freely.  This  mist  consists  of  fine  par- 
ticles of  electrolyte. 

Starting  Rate:  The  rate  used  when  starting  a charge.  This  rate  may  be  in  excess  of  the  normal 
rate  and  is  not  injurious  unless  the  temperature  rises  above  105°  F.,  or  heavy  gassing  is  caused. 

Strap:  The  lead  connector  which  binds  all  plates  of  like  polarity  into  one  group. 

Sulphate:  A popular  term  for  lead  sulphate. 

Sulphated:  The  condition  of  a cell  which  is  under-charged.  This  is  due  to  insufficient  charge  or 
“self-discharge.” 

Sulphate  Reading:  The  abnormal  voltage  reading  when  a sulphated  battery  is  placed  on  charge. 

Terminal:  The  post  to  which  outside  wires  are  connected  to  the  battery. 

Vent  Cap:  The  cap  for  the  filling  tube  constructed  so  as  to  permit  the  escape  of  g'asses  and  prevent 
the  spilling  of  electrolyte: 

Vitriol:  Term  used  for  “Oil  of  Vitriol”  or  concentrated  sulphuric  acid. 

Volt:  The  unit  of  measurement  used  to  measure  electrical  pressure. 

Washing:  Removal  of  mud  from  the  jars  and  rinsing  of  the  plates. 

Watt:  The  unit  used  to  measure  electrical  power.  The  wattage  of  a circuit  is  the  product  of  the 
voltage  and  amperage. 

Watt-hour:  The  unit  of  electrical  work.  The  product  of  watts  and  hours. 


Copyright  1922,  B.  B.  Burling 
Bruce.  Milwaukee,  Publishers 


ljoose  Leaf  Shop  Manual 
Burling  Vocational  Series 
Battery  Testing  and  Repair 


Job  A-l— THE  CONSTRUCTION  OF  A STORAGE  BATTERY 

Object — To  become  familiar  with  the  detailed  construction  of  a starting  and  lighting  battery  of 
standard  make. 

Apparatus — A six  volt  storage  battery  which  has  either  been  sectioned  or  a battery  which  is  dry 
and  suitable  for  disassembling. 

Method 

1 —  Examine  the  exterior,  carefully  noting  the  information  given  on  the  name  plate  and  other  de- 
tails which  may  be  peculiar  to  the  size  and  make  of  battery. 

2 —  Open  the  battery  with  the  utmost  care  so  as  to  note  all  the  details  of  construction  and  be  able 
to  reassemble  the  battery  properly. 

The  following  sketch  represents  the  average  battery. 

Name  the  parts  and  state  wherein  the  sketch  differs  from  the  battery  examined. 


Answer  the  following  from  your  observation: 

1 —  What  is  the  color  of  the  plates  connected  to  the  -f-  terminal? 

2 —  What  is  the  color  of  the  plates  connected  to  the  — terminal? 

3 —  How  many  -f-  plates  are  there  in  each  group? 

4 —  How  many  — plates  are  there  in  each  group? 

5 —  Why  is  there  one  more  negative  plate  than  positive? 

6 —  What  are  the  separators  for? 

7 —  Which  side  of  the  separator  faces  the  pos.  plate?  Why? 

8 —  Of  what  are  the  separators  made? 

9 —  How  are  the  separators  held  in  place? 

10 —  What  is  the  space  in  the  bottom  of  the  jar  for? 

11 —  Name  fifteen  uses  for  storage  batteries. 

12 —  How  many  covers  has  the  battery?  Why? 

13 —  How  is  the  battery  sealed  to  prevent  “slopping?” 

14 —  Of  what  material  is  the  jar  composed? 

15 —  Why  is  the  vent  cap  constructed  as  it  is? 

16 —  Why  cannot  a cork  be  used? 

17 —  What  metal  is  used  for  the  connectors?  Why? 

18 —  Of  what  material  is  the  case  composed? 

19 —  Is  it  protected  in  any  way?  How? 

20 —  Of  what  material  are  the  plates  (grids)  made?  Why? 


Copyright  1922,  B.  B.  Burling 
Bruce,  Milwaukee,  Publishers 


Loose  Leaf  Shop  Manual 
Burling  Vocational  Series 
Battery  Testing  and  Repair 


Theory — The  term  storage  battery  is  misleading  inasmuch  as  no  electrical  energy  is  actually  stored 
up  in  a battery.  A battery  is  a store  house  of  chemical  energy  which,  upon  demand  can  be  changed  into 
electrical  energy.  In  other  words  a battery  is  a device  used  to  change  chemical  into  electrical  energy, 
and  a storage  battery  is  a (reversible)  device  in  which  electrical  energy  can  be  changed  to  chemical  and 
chemical  back  again  into  electrical.  The  terminals  of  a battery  are  labeled  + and  — indicating  the 
“poles”  of  the  cell  from  which  electric  energy  passes  to  the  external  circuit  and  returns. 

The  chemical  action  which  takes  place  with  a flow  of  current  is  not  hard  to  understand  and  will  be 
discussed  later,  but  the  cause  of  the  existence  of  electrical  energy  cannot  be  explained  here  any  further 
than  to  say  that  between  every  conductor  and  the  medium  surrounding  it  there  is  an  electrical  pres- 
sure. This  electrical  pressure  causes  a flow  of  electrical  energy  when  a conducting  medium  is  present. 

With  the  flow  of  electrical  energy  there  is  a consumption  of  material  inside  the  cell.  This  consump- 
tion is  concentrated  largely  at  the  plate  connected  to  the  negative  terminal.  Hence  this  plate  is  gener- 
ally called  the  “positive”  or  “fuel  producing”  electrode.  In  the  lead  storage  battery  this  plate  or  elec- 
trode is  composed  of  “spongy”  lead  and  it  is  from  this  plate  that  the  electrical  energy  starts  on  its  cycle 
through  the  cell  to  the  “peroxide”  electrode,  and  thence  to  the  external  circuit. 

With  the  passage  of  electric  current  through  a solution  decomposition  takes  place.  This  principle 
is  made  use  of  in  restoring  (recharging)  a cell  to  its  former  condition  after  it  has  expended  its  chemical 
energy  in  forcing  electric  current  through  the  external  circuit  when  on  discharge. 


Copyright  1922,  B.  B.  Burling 
Bruce.  Milwaukee,  Publishers 


Loose  Leaf  Shop  Manual 
Burling  Vocational  Series 
Battery  Testing  and  Repair 


Job  A-2— THE  CONVERSION  OF  CHEMICAL  INTO  ELECTRICAL  ENERGY. 

Object — To  become  familiar  with  the  principle  of  all  batteries,  more  especially  primary  cells. 

Apparatus — Small  pieces  of  sheet  copper,  aluminum,  lead,  iron,  carbon,  zinc,  lead,  a piece  of  old  pos. 
storage  battery  plate,  or  any  other  metals  available.  A low  reading  voltmeter,  weak  sulphuric  acid, 
and  a glass  battery  jar. 

Method — Place  the  strips  of  metal  or  elements  in  the  jar  of  acid,  two  at  a time,  and  connect  to 
the  voltmeter,  record  the  deflection  or  throw  of  the  needle.  (Be  sure  the  metals  are  cleaned  before 
use).  Record  the  groups  of  combinations  in  the  order  of  deflections.  It  will  be  noticed  that  the  sub- 
stances giving  the  greatest  throw  of  the  needle  are  the  substances  which  are  used  commercially  for 
battery  purposes. 

Record  the  elements  in  the  order  of  their  activity  as  indicated  by  meter  deflections. 

Questions 

1 —  Did  the  position  of  the  needle  of  the  voltmeter  remain  constant  when  the  circuit  was  kept 
closed?  Why?  (Observe  especially  when  copper  and  zinc  are  the  elements). 

2 —  What  is  a positive  element? 

3 —  What  is  a positive  terminal? 

A — From  your  observations  which  group  would  you  select  if  your  were  constructing  a primary  cell? 
Why? 

5 —  Test  this  group  again  permitting  the  circuit  to  remain  closed  for  ten  minutes.  Does  the  needle 
deflection  remain  constant? 

6 —  Clean  the  elements  used  above  (5)  and  test  again.  Is  the  throw  of  meter  needle  the  same  as 
in  (5)  ? Why?  There  is  evidently  a condition  at  the  surface  of  at  least  one  of  the  elements  which,  if  re- 
moved, would  increase  the  cell’s  activity. 

7 —  Did  the  separation  of  the  elements  influence  the  meter  reading?  Why? 

8 —  What  deflection  was  noticed  when  the  elements  were  in  contact  within  the  solution? 

9 —  If  you  were  constructing  a battery  would  you  want  a wide  separation  between  plates?  Why? 

Theory — It  is  evident  from  the  results  of  the  test  that  some  metals  are  extremely  active  in  a solu- 
tion of  sulphuric  acid.  Chemical  action  should  be  suppressed  as  much  as  possible,  and  for  this  reason 
the  zinc  element,  which  is  one  of  the  most  active,  is  generally  amalgamated.  (Amalgamation  is  done 
by  rubbing  mercury  onto  the  surface  of  the  zinc.  The  mercury  will  unite  with  and  protect  the  ex- 
posed metal). 

If  other  solutions,  as  sal  ammoniac,  were  used  it  would  be  noticed  that  the  action  is  much  weaker. 
It  is,  however,  interesting  to  note  that  the  size  of  plate  in  solution,  or  the  distance  the  plates  are  apart, 
have  no  noticeable  effect  upon  the  deflection.  It  is  evident,  therefore,  that  the  voltage  or  force  which 
causes  the  current  to  flow  is  not  dependent  upon  size,  shape,  or  distance  between  the  plates,  but  upon 
nature  of  the  elements  and  the  solution. 

The  effect  of  the  electric  current  upon  the  elements  when  a cell  is  discharging  is  to  use  up  one  or 
both.  There  is  also  a change  in  the  electrolyte  showing  that  there  is  a chemical  reaction  taking  place 
with  the  flow  of  electric  current.  A primary  cell  may  be  defined  as  a cell  in  which  the  elements  must 
be  replaced  after  the  cell  has  been  depleted  by  use.  In  other  words,  it  is  an  apparatus  used  to  change 
chemical  into  electrical  energy. 

Due  to  the  fact  that  the  voltage,  and  hence  the  current  do  not  remain  constant  in  service, 
batteries  of  the  types  tested  are  only  used  for  open  circuit  work.  Several  modifications  have  been 
made  to  overcome  the  inherent  defects  of  this  type  of  cell  by  eliminating  the  cause  of  voltage  drop 
namely : polarization. 

Further  tests  will  be  made  on  polarization  later. 


Copyright  1922,  B.  B.  Burling 
Bruce.  Milwaukee.  Publishers 


( 


BK 

, ... 


Loose  Leaf  Shop  Manual 
Burling  Vocational  Series 
Battery  Testing  and  Repair 


Job  A-3— THE  HYDROMETER  AND  THERMOMETER 

Object To  understand  the  principle  of  and  uses  of  the  hydrometer  and  the  influence  which  tem- 

perature has  upon  its  reading. 

Apparatus — A commercial  battery  hydrometer,  a floating  thermometer  reading  from  zero  to  about 
120°,  some  battery  acid,  an  earthen  container,  and  a heating  unit. 

Method 

1  if  the  hydrometer  being  tested  has  a Baume  and  a Specific  Gravity  scale,  examine  and  de- 

termine Baume  readings  and  equivalent  gravity  readings.  Plot  a curve  showing  the  relationship 
between  the  two  systems  of  testing  acid  strength. 

2  If  the  weather  is  cold,  place  some  acid  outside  to  cool  and  take  readings  of  gravity  and  tempera- 

ture (F.)  through  a range  of  at  least  fifteen  degrees.  If  ice  is  available  the  test  can  be  performed  indoors. 
In  case  it  is  inconvenient  to  cool  the  acid  arrange  some  means  of  heating  enough  acid  for  testing  and 
take  readings  of  gravity  and  temperature  (F.)  through  a range  of  about  30°  F.  From  this  data  cal- 
culate the  increase  or  decrease  in  gravity  for  each  three  degrees  change  in  temperature.  Average  the 
results  obtained. 

Questions 

1 —  What  degree  Baume  is  equivalent  to  1.300  sp.  gr?  Fig.  5. 

2 —  What  effect  does  a change  in  temperature  have  upon  Baume  readings?  Figs.  5,  6. 

3  What  is  the  gravity  reading  at  zero  degrees  F.  of  acid  testing  1.280  at  70°  F.? 


Commercial  Types 


Fig.  5. 


JD?$rt>es  Cor  re  chon  For 


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Fig.  6. 


Theory — The  specific  gravity  of  a solution  is  the  weight  of  a given  volume  compared  with  a like 
volume  of  water.  The  specific  gravity  of  water  is  1.00.  If  pure  acid  has  a gravity  of  1.83  it  is  1.83  times 
heavier  than  water. 

There  is  an  expansion  or  contraction  of  most  substances  when  subjected  to  a change  in  tempera- 
ture. This  change  in  volume  without  change  in  weight  simply  means  that  the  weight  of  a definite 
volume  fluctuates  with  changes  of  temperature. 

The  buoyant  effect  is  always  equal  to  the  weight  of  the  liquid  displaced  so  a hydrometer  can  be 
graduated  to  measure  the  weight  of  the  solution  displaced  and  as  this  weight  changes,  due  to  fluctuat- 
ing temperatures,  the  reading  on  the  hydrometer  will  show  a corresponding  change. 


Copyright  1922,  B.  B.  Burling 
Bruce,  Milwaukee,  Publishers 


* 

* 

; * • «i  ■' 


Loose  Leaf  Shop  Manual 
Burling  Vocational  Series 
Battery  Testing  and  Repair 


Job  A-4— THE  ELECTROLYTE 

Object — To  determine  the  properties  of  battery  acid.  Methods  of  handling.  Mixing.  Propor- 
tions acid  and  water,  etc. 

Apparatus — An  earthen  container.  A means  for  measuring  acid  and  water,  concentrated  acid,  dis- 
tilled water,  hydrometer,  thermometer  and  storage  battery  being  charged. 

Method 

1 —  Measure  out  carefully  five  (5)  portions  of  pure  water,  and  then  carefully  (while  stirring)  pour 
into  the  water  two  (2)  portions  of  acid.  Test  with  the  hydrometer  and  thermometer  and  calculate  the 
gravity  at  70°  F. 

2 —  Measure  the  electrolyte  and  explain  the  cause  for  any  noticeable  discrepancy. 

3 —  You  will  probably  not  be  able  to  measure  the  expansion  or  contraction  of  the  solution  due  to 
temperature  changes,  but  calculate  the  per  cent  expansion  for  a change  of  forty  (40)  degrees  F. 

4 —  Is  this  sufficient  to  cause  a normal  battery  to  overflow  when  on  charge  ? 

5 —  Explain  the  reasons  for  a “slopping”  battery. 

6 —  Test  each  cell  of  the  battery  carefully  with  hydrometer  and  thermometer  and  explain,  if  possible, 
the  cause  of  any  variation  in  acid  readings. 

Questions 

1 —  What  proportions  of  acid  and  water  are  there  in  commercial  battery  acid? 

2 —  Are  these  proportions  by  weight  or  volume? 

3 —  What  kind  of  container  should  be  used  for  acid?  Why? 

4 —  Describe  the  method  of  “mixing  acid.” 

5 —  Does  acid  evaporate? 

6 —  How  often  would  you  “water  the  battery?”  Why? 

7—  Explain  why  two  portions  of  acid  and  five  portions  of  water  do  not  make  seven  portions  of 
electrolyte. 

8 —  When  should  acid  be  added  to  a battery? 

9 —  Explain  why  the  middle  cell  should  be  watched. 

10 —  What  kinds  of  water  should  be  used  in  a battery? 

11 —  When  should  water  be  added  to  a battery  in  winter?  Why? 

12 —  What  dangers  and  difficulties  are  involved  in  a “slopping”  battery? 

13 —  How  high  above  the  plates  should  the  electrolyte  be  in  a battery?  How  low? 

14 —  Why  not  fill  the  battery  full  when  adding  water? 

15 —  Why  should  spilled  acid  or  water  around  a battery  be  immediately  neutralized  and  wiped  off? 

16 —  What  is  meant  by  HsSO»? 

17 —  Where  there  is  a large  quantity  of  acid  (electrolyte)  in  a battery  why  is  the  density  generally 
lower  than  where  there  is  a limited  quantity? 

18 —  Is  a metal  container  suitable  for  water  storage?  Why? 

Theory — The  electrolyte  of  the  commercial  lead  cell  is  sulphuric  acid  (HsSO«)  composed  of  hydro- 
gen, sulphur  and  oxygen  in  chemical  union  plus  sufficient  pure  water  to  reduce  it  to  the  desired  density. 

Pure  acid  has  a specific  gravity  of  1.835.  This  acid  is  so  strong  that  it  will  char  wood,  cause  water 
to  boil  and  burn  the  skin.  The  affinity  which  concentrated  acid  has  for  water  is  largely  the 
cause  of  the  above  and  other  properties.  It  is  difficult  to  realize  the  care  which  must  be  exer- 
cised in  maintaining  a pure  electrolyte.  Electrochemical  action  is  always  present  and  the  addi- 
tion of  impurities  in  the  water  or  the  acid  will  in  time  cause  a disintegration  of  the  positive  plates 
and  a local  action  discharge  of  the  negative.  “A  little  won’t  hurt,”  you  are  likely  to  say,  but  with  the 
realization  that  every  week  or  two  throughout  the  year  water  is  added  to  the  cells  it  becomes  evident 
that  impurities  are  liable  to  accumulate  in  dangerous  proportions. 

The  properties  of  strong  acid  naturally  lead  to  the  assumption  that  these  properties  exist  in  the 
ordinary  electrolyte.  This  is  to  some  extent  the  case  although  less  in  degree.  The  wood  separators  are 
liable  to  decompose  under  the  action  of  acid  and  temperature.  Keep  the  acid  below  1.300  and  105°  F. 

During  the  normal  use  of  a battery  water  only  is  evaporated  and  hence  water  should  only  be  used 
to  replace  the  loss.  The  addition  of  electrolyte,  to  take  care  of  this  evaporation,  would  mean  a high 
gravity  on  full  charge  and  a resultant  shortening  of  the  battery’s  life.  Never  add  acid  until  you  are 
certain  the  low  gravity  is  due  to  sloppage  or  leakage. 


Copyright  1922,  B.  B.  Burling 
Bruce,  Milwaukee,  Publishers 


Loose  Leaf  Shop  Manual 
Burling  Vocational  Series 
Battery  Testing  and  Repair 


In  order  to  determine  the  condition  of  a battery  individual  cell  readings  should  be  taken,  although 
weekly  readings  of  the  middle  cell  are  recommended  as  this  cell  generally  gives  trouble  first. 

When  plates  are  immersed  in  electrolyte  a gradual  change  takes  place  and  the  sulphate  (SO«)  of  the 
acid  unites  with  the  active  material  of  the  plates.  This  is  called  “sulphation.”  Periodic  charges  at  least 
once  a month  are  necessary  to  keep  any  battery  in  good  condition. 

During  the  process  of  sulphation  (battery  discharge),  whether  through  use  or  through  idleness, 
the  acid  becomes  weaker  until  the  battery  will  act  sluggishly,  or  even  fail  to  turn  “ the  engine  over.” 
Such  weak  acid  freezes  easily.  The  electrolyte  of  a battery  in  a charged  condition  (1.300)  cannot 
freeze.  In  cold  weather  a battery  should  be  maintained  in  a charged  condition.  Any  cell  which 
shows  a “low  gravity”  (weak  acid)  should  be  examined  carefully  to  determine  and  relieve  the  cause 
before  freezing,  breakage,  or  other  damage  is  done.  Chemicals  like  ammonia  and  soda  neutralize  acid. 
Always  keep  some  on  hand. 


Copyright  1922,  B.  B.  Burling 
Bruce.  Milwaukee,  Publishers 


Loose  Leaf  Shop  Manual 
Burling  Vocational  Series 
Battery  Testing  and  Repair 


V 


job  A-5— THE  VOLTMETER 


Object To  study  several  types  of  D.  C.  voltmeters,  check  their  accuracy  and  connections. 

Apparatus — A pocket  type  of  voltmeter.  A permanent  magnet  meter  (preferably  a Weston),  a 
source  of  electrical  energy  of  sufficient  voltage  to  test  each  scale  of  the  meters,  and  suitable  resistances. 

Method 

I.  Examine  each  meter  very  carefully,  recording  the  following  points : 

(a)  The  type  of  meter,  number,  and  name  of  manufacturer. 

(b)  The  range  of  scale  or  scales. 

(c)  The  construction:  permanent  parts,  movable  parts,  bearings,  zero  correction  and 
damping. 

(d)  Internal  wiring  diagram  and  connections. 

(e)  Test  parts  with  a compass.  State  results. 

II.  Show  by  diagram  the  method  used  in  placing  a voltmeter  in  a circuit  to  test  the  voltage  of  a 
battery  and  the  voltage  across  an  incandescent  lamp. 


Fig.  7. 


III.  Arrange  suitable  resistances  or  lamps  as  shown  in  the  diagram  and  connect  the  pocket  and 
standard  meters  as  indicated.  Shift  the  connections  as  shown  and  take  simultaneous  readings  of  both 
meters.  Plot  the  data  obtained  with  the  standard  meter  readings  on  the  horizontal,  and  the  pocket 
meter  readings  on  the  vertical.  For  very  accurate  testing  all  meters  should  be  thus  calibrated  at  fre- 
quent intervals  and  the  “calibration  curve”  used  to  correct  subsequent  readings. 

Questions 

1.  What  would  take  place  if  the  direction  of  current  were  reversed  through  the  meter? 

2.  Is  this  true  with  every  meter? 

3.  If  the  magnet  were  accidentally  reversed  what  would  be  the  result? 

4.  Would  temperature  affect  the  readings  of  the  meters  tested?  Why? 

5.  What  would  be  the  result  if  the  meter  were  connected  in  line  with  the  current?  Connect  thus 
and  explain. 

6.  What  method  could  be  devised  to  use  a low  reading  voltmeter  on  a higher  voltage  line  than 
the  range  of  the  meter  would  indicate? 

7.  Is  this  method  used  in  a two  or  more  range  meter? 

8.  Would  it  be  possible  to  use  the  meters  tested  on  alternating  current?  Why? 

Theory — Direct  current  voltmeters  in  general  use  are  of  three  types : solenoidol,  permanent  magnet 
and  electrodynamometer,  although  for  special  purposes  hot  wire  or  electrostatic  meters  may  be  used. 
Probably  the  oldest  style  of  meter  is  the  solenoidol  or  movable  core  type. 

The  fundamental  principle  involved  in  most  of  the  commercial  meters  is  magnetic  attraction  and 
repulsion.  In  the  solenoidol  type  a core  to  which  is  attached  an  indicator,  or  pointer  is  magnetically 
attracted  into  the  solenoid.  The  extent  of  movement  is  naturally  proportioned  to  the  attraction,  and 
the  attraction  is  in  turn  proportional  to  the  current  flowing  through  the  coils.  The  amount  of  current 
flowing  through  the  coil  or  coils  is  proportioned  to  the  electrical  pressure  (voltage)  back  of  the 
current,  hence  the  movement  of  the  core  or  plunger  is  proportional  to  the  voltage.  The  best  volt- 
meters have  a very  high  resistance  and  their  current  is  practically  negligible.  Cheap  pocket,  portable 
or  wall  instruments  are  seldom  very  reliable.  In  meters  of  fixed  polarity  it  naturally  follows  that  there 
must  be  a certain  direction  of  current  in  order  to  produce  a definite  second  polarity  and  cause  a cor- 
rect indication.  This  principle  is  also  noticed  when  a magnet  is  brought  near  a compass.  One  pole 
attracts  and  the  other  repels.  In  meters  the  polarities  may  be  produced  by  a permanent  magnet  and 
a solenoidol  magnet,  or  by  two  solenoidol  magnet  coils.  The  Weston  D.  C.  meter  is  typical  of  the 
permanent  magnet  and  solenoidol  magnet  coil. 

All  meter  movements  must  be  “damped”  so  as  to  avoid  oscillation  of  the  needle.  This  may  be  done 
by  mechanical  or  electrical  means.  Air,  oil  and  other  liquids  have  been  used  with  success.  Natur- 
ally air  would  be  best  suited  for  portable  and  oil  for  wall  or  stationary  meters.  The  electrical  method 
of  damping  is  by  the  formation  of  “eddy”  currents  in  the  movable  parts  of  the  meter.  These  electric  cur- 
rents are  caused  when  any  conducting  material  is  moved  in  a magnetic  field,  as  would  be  the  case  when 
the  movable  part  of  the  meter  oscillates  in  the  permanent  or  electromagnetic  field.  The  effect  of  the 
eddy  currents  is  to  oppose  the  motion  which  creaJed  them.  This  is  what  prevents  any  appreciable 
oscillation  of  the  needle  in  the  best  types  of  porta'  le  meters. 


Copyright  1922,  B.  B.  Burling 
Bruce,  Milwaukee,  Publishers 


•'  .1. 


1 


V * • • 


Loose  Leaf  Shop  Manna] 
Burling  Vocational  Series 
Battery  Testing  and  Repair 


Job  A-6— THE  AMMETER 

Object — To  study  several  types  of  D.  C.  ammeters  check  their  accuracy  and  connections. 

Apparatus— A pocket  type  of  ammeter,  one  or  more  portable  meters  of  standard  make,  source 
of  electrical  energy  (six  volt  storage  battery)  and  suitable  regulating  resistance. 

Method 

I.  Examine  each  meter  carefully  recording  the  following  information : 

(a)  Type  of  meter,  maker’s  name  and  meter  number. 

(b)  The  range. 

(c)  The  construction,  permanent  parts,  movable  parts,  bearings,  zero  correction  and  damping. 

(d)  Internal  wiring  diagram  and  connections. 

(e)  Test  parts  with  compass.  State  results. 

II.  Show  by  diagram  the  method  of  connecting  an  ammeter  in  a circuit. 

III.  Arrange  a variable  resistance  in  series  with  the  various  meters  being  tested  and  connected 
to  a six  volt  source  of  energy.  Adjust  the  resistaice  so  that  simultaneous  readings  can  be  taken  of  all 
meters  at  different  points  on  the  scale.  Plot  the  data  for  the  standard  or  most  accurate  meter  on  the 
horizontal  and  the  other  data  on  the  vertical. 

Questions 

1.  What  effect  would  a reversal  of  current  through  the  ammeters  tested  have?  Why? 

2.  How  is  the  range  of  a meter  changed? 

3.  Explain  how  you  would  measure  a thirty  ampere  current  with  a five  ampere  range  meter. 
What  properties  should  the  metal  to  be  used  for  the  shunt  have? 

4.  Dry  cells  are  generally  tested  with  an  ammeter.  Why  would  it  be  disastrous  to  attempt  to 
test  a storage  battery  in  the  same  way? 

5.  Can  the  meters  be  used  on  A.  C.?  Why? 

Theory — The  D.  C.  Ammeters  are  of  the  same  types  as  explained  under  voltmeters  and  the  theory 
of  operation  is  the  same.  In  the  construction  of  an  ammeter  the  resistance  is  negligible  or  very  low, 
while  in  the  voltmeter  the  resistance  is  high.  This  explains  why  a voltmeter  can  be  connected  directly 
across  a line  while  an  ammeter  would  burn  out  if  so  treated. 


Copyright  1922,  B.  B.  Burling 
Bruce.  Milwaukee,  Publishers 


Loose  Leaf  Shop  Manual 
Burling  Vocational  Series 
Battery  Testing  and  Repair 


Job  A-7— POLARIZATION  OF  PRIMARY  CELLS 

Object — To  study  the  characteristics  of  commercial  primary  cells. 

Apparatus — A dry  cell,  Edison  primary  cell,  gravity  cell,  ammeter,  voltmeter  and  suitable  re- 
sistance. 

Method 

Short  circuit  each  of  the  cells  through  a resistance,  reading  the  amperage  and  voltage  every  min- 
ute for  ten  minutes.  (At  each  minute  interval  open  the  circuit  for  an  instant  and  record  the  voltage.) 
Record  the  voltage  when  cells  are  on  open  circuit  and  also  the  instant  the  switch  is  closed  for  the  dis- 
charge. After  the  discharge  of  ten  minutes  open  the  circuit  and  immediately  read  the  voltage.  (Con- 
tinue to  take  voltage  readings  every  half  minute  until  the  readings  cease  to  change.) 

Plot  the  data  obtained  from  each  of  the  three  cells  and  in  the  write-up  compare, 

1st — Voltage  discharge  curves. 

2nd — Voltage  polarization  curves. 

3rd — Voltage  recuperation  curves. 

Questions 

1.  Which  of  the  cells  tested  would  be  most  suitable  for  open  circuit  work?  Why? 

2.  Which  would  be  most  suitable  for  closed  circuit  work?  Why? 

3.  State  various  commercial  uses  for  open  and  closed  circuit  batteries. 

4.  Explain  the  construction  of  each  cell  tested  including  the  elements  used,  the  electrolyte, 
depolarizer,  etc. 

5.  Explain  the  action  which  takes  place  in  each  type  of  cell  when  on  discharge. 

6.  Is  it  possible  to  charge  a dry  cell  by  the  passage  of  an  electric  current?  Why? 

7.  What  common  test  is  used  to  determine  the  condition  of  dry  cells? 

8.  Is  this  an  entirely  satisfactory  method  of  testing?  Why? 

9.  Can  the  same  method  be  used  in  testing  storage  batteries?  Why? 

Theory — The  fact,  known  to  all  electro-platers  and  electro-chemists,  that  metals  including  hydro- 
gen, pass  through  a solution  in  the  direction  of  the  current,  gives  us  an  explanation  for  polarization. 
When  an  electric  current  flows  through  a water  solution  decomposition  takes  place,  and  hydrogen, 
travelling  with  the  current,  is  deposited  on  the  “positive  plate.”  If  the  hydrogen  is  not  taken  care  of 
by  chemical,  electro-chemical  or  mechanical  means  it  will  set  up  a voltage  in  opposite  direction  to  the 
flow  of  current.  This  is  the  situation  which  exists  in  what  is  known  as  a polarized  cell.  In  all  com- 
mercial primary  cells  so  called  “oxydizing  agents”  are  used  because  hydrogen  and  oxygen  have  a 
great  affinity  for  each  other.  The  union  of  two  parts  of  hydrogen  to  one  of  oxygen  forms  water  and 
is  expressed  chemically  as  HaO.  The  oxygen  may  be  supplied  in  the  plate  as  a part  of  the  element, 
or  in  the  medium  surrounding  it.  Both  methods  are  used  commercially.  In  the  Edison  primary  cell 
the  oxygen  in  the  copper  oxide  plate  is  used  up  in  overcoming  polarization.  In  the  dry  cell  the 
manganese  dioxide  surrounding  the  carbon  element  is  used  for  the  same  purpose. 

When  ignition  for  motor  vehicles  was  performed  with  dry  cells,  it  was  necessary  to  develop  an 
open  circuit  system  so  as  to  prolong  the  useful  rife  of  the  cells  and  give  opportunity  for  the  depolar- 
izer to  do  its  effective  work.  The  well  known  Atwater-Kent  system  proved  one  of  the  most  efficient. 
Other  systems  of  the  closed  circuit  type  proved  too  much  of  a drain  upon  the  cells  and  made  it  ab- 
solutely necessary  to  use  a non-polarizable,  or  a storage  battery. 


Copyright  1922,  B.  B.  Burling 
Bruce,  Milwaukee,  Publishers 


H8E 


Loose  Leaf  Shop  Manual 
Burling  Vocational  Series 
Battery  Testing  and  Repair 


Job  A-8— SERIES  AND  PARALLEL  COMBINATION  OF  CELLS 

Object — To  study  the  effect  of  various  combinations  of  cells  upon  ammeter  and  voltmeter  readings. 

Apparatus — D.  C.  Ammeter,  D.  C.  Voltmeter,  flash  light  battery,  three  No.  6 dry  cells,  and  a three 
volt  flash  light  bulb,  (storage  cells  are  not  used  in  this  test  because  of  accidental  wrong  connections.) 
with  an  ammeter  and  a dry  cell. 

Method 

I.  (a)  Measure  the  voltage  of  the  flash  light  battery  cell  and  the  voltage  of  a No.  6 dry  cell. 

Explain. 

(b)  Connect  two  dry  cells  in  series,  measure  the  voltage  of  the  combination. 

(c)  Connect  three  dry  cells  in  series,  measure  the  voltage  of  the  combination. 

(d)  Connect  a flash  light  cell  and  three  dry  cells  in  series,  measure  the  voltage  of  the  com- 
bination. 

(e)  Reverse  one  of  the  cells,  and  test  voltage  of  the  combination.  Explain. 

(f)  Make  a commercial  “flash  test”  of  the  dry  cells  individually. 

(g)  Make  a flash  test  of  two  dry  cells  connected  in  series.  Be  sure  that  these  two  cells  have 
practically  the  same  individual  flash  tests. 

(h)  Connect  these  two  cells  in  parallel.  Test  voltage  and  flash. 

II.  (a)  Connect  the  flash  light  bulb  in  series  with  an  ammeter  and  a dry  cell.  Test  voltage  across 
cell  when  delivering  current. 

(b)  Connect  in  series  with  two  dry  cells.  Note  reading.  Test  voltage  across  each  cell 
when  current  is  flowing. 

(c)  Connect  three  cells  in  series  and  test  likewise.  How  do  the  readings  of  the  ammeter 
and  voltmeter  differ  when  the  lamp  is  connected  in  the  circuit?  Explain. 

(d)  Connect  two  dry  cells  in  parallel  with  the  lamp.  Note  readings  of  current,  and  test 
voltage  across  each  cell. 

(e)  Connect  three  dry  cells  in  parallel  with  the  lamp.  Note  current  reading  and  test  voltage 
across  each  cell. 

(f)  What  effect  does  the  addition  of  cells  in  parallel  have  upon  the  current  through  an  external 
resistance  circuit?  How  does  this  differ  from  the  data  obtained  when  cells  were  connected  in  series 
with  practically  no  external  resistance  as  in  the  flash  text? 

• (g)  How  does  the  cell  voltage  change  when  delivering  current? 

Theory — From  the  discussion  given  under  Job  No.  2,  it  will  be  remembered  that  different  metals 
immersed  in  an  electrolyte  gave  correspondingly  different  voltages.  It  was  probably  also  noted  that 
the  surface  exposed  to  the  electrolyte  had  no  appreciable  effect  upon  the  voltmeter  readings. 

In  primary  batteries,  such  as  the  drycell,  the  internal  resistance  is  quite  high  although  not  as  high 
as  in  the  gravity  or  wet  cell.  In  short  circuit  (flash)  tests  this  internal  resistance  limits  the  flow  of 
current.  A storage  cell  with  the  plates  close  together,  an  electrolyte  of  very  good  conductivity  and  a 
large  plate  area  has  a very  low  internal  resistance.  This  accounts  for  the  fact  that  high  amperages 
of  several  thousand  can  be  obtained  on  a dead  short.  (Never  short  circuit  a storage  battery). 

The  plates  of  the  ordinary  storage  cell  are  connected  in  parallel  and  thus  increase  the  current  out- 
put without  changing  the  voltage.  Other  things  being  equal  a battery  (cell)  of  more  plates  will  deliver 
considerable  more  current  than  one  of  fewer  plates.  When  storage  batteries  were  only  used  for 
lighting  and  ignition,  large  amperage  output  with  large  plate  area  was  unnecessary,  but  with  a cur- 
rent demand  of  from  100  to  200  amperes  every  time  the  engine  is  started,  it  is  necessary  to  have  a bat- 
tery of  greater  plate  area. 

The  cells  of  a battery  are  connected  in  series  to  give  six  or  twelve  volts  as  desired.  The  com- 
mercial starting  and  lighting  battery  is  a parallel  series  combination  of  plates.  In  parallel  to  give 
high  amperage  and  in  series  to  give  voltage. 

The  terminal  voltage  (voltage  when  on  discharge)  is  a changing  quantity  depending  upon  the  rate 
and  duration  of  discharge.  The  difference  between  the  open  circuit  voltage  and  terminal  voltage  is 
the  pressure  lost  in  forcing  the  current  through  the  cell  or  battery.  The  lower  the  internal  resistance, 
the  higher  the  terminal  voltage,  and  the  more  “pep”  the  battery  has. 

The  high  internal  resistance  of  the  “Edison”  storage  cell  makes  it  less  suitable  for  starting  pur- 
poses. 


Copyright  1922,  B.  B.  Burling 
Bruce,  Milwaukee,  Publishers 


Loose  Leaf  Shop  Manual 
Burling  Vocational  Series 
Battery  Testing  and  Repair 


Job  A-9— CHARGING  BATTERY  USING  HYDROMETER  FOR  TESTING. 

Object — To  become  familiar  with  the  use  of  a hydrometer  in  testing  the  state  of  charge  of 
a battery. 

Apparatus — A storage  cell,  or  preferably  a six  volt  battery,  hydrometer,  thermometer,  source  of 
D.  C.  energy  for  charging,  an  ammeter  and  a regulating  resistance. 

Method 

1.  Examine  battery  and  determine  charging  rate  from  name  plate.  (See  theory). 

2.  Determine  by  test  whether  the  supply  of  energy  is  direct  or  alternating. 

3.  Be  sure  the  plates  of  each  cell  are  properly  covered  with  electrolyte.  If  not  supply  distilled 
water  up  to  the  proper  height  (about  above  top  of  plates). 

4.  Start  the  battery  charging  at  the  normal  or  ten  hour  rate,  and  test  the  gravity  of  each  cell  at 
hourly  intervals  until  three  successive  readings  show  no  change. 

5.  Test  the  temperature,  make  correction  of  gravity  readings  for  70°  F.  and  equalize  the  acid  if 
necessary. 

6.  Continue  charge  for  one  hour  to  insure  proper  mixing  of  acid  and  water.  Test  again  and  re- 
peat equalization  and  further  charge  if  necessary. 

Questions 

1.  What  different  methods  can  be  used  to  determine  whether  the  energy  available  is  D.  C.  or 
A.  C.  ? 

2.  Why  is  not  A.  C.  used  to  charge  a battery? 

3.  Explain  completely  how  you  would  charge  a battery,  maximum  temperature  permissible, 
charging  rate,  gravity,  and  direction  of  current  through  battery? 

4.  When  did  gassing  begin?  Is  this  any  indication  of  condition  of  charge? 

5.  Was  there  any  noticeable  change  in  the  color  of  the  plates  during  charge?  What? 

In  case  the  gravity  fails  to  rise  or  show  a change  after  an  hour’s  charge  the  battery  should  be  sent 
to  the  repair  room.  Where  many  batteries  are  being  charged  hourly  readings  on  all  should  be  made. 
In  order  to  know  how  the  cells  are  “coming  up”  distinctive  chalk  marks  can  be  placed  on  each  battery 
when  making  the  round.  The  following  markings  have  proven  very  satisfactory. 

Distinctive  Marks  Gravity  Readings 


—5 

1.255 

— 4 

1.260 

—3 

1.265 

—2 

1.270 

— 1 

1.275 

— or  0 

1.280 

+ 1 

1.285 

+2 

1.290 

+3 

1.295 

+4 

1.300 

Theory — The  term  ampere  hour  is  used  frequently  in  connection  with  storage  battery  work  and 
is  equal  to  the  product  of  the  flow  of  the  current  in  amperes  and  the  time  the  flow  is  maintained. 
Thus,  a discharge  of  ten  (10)  amperes  for  10  hours  indicates  that  the  battery  has  a capacity  of  at  least 
100  ampere  hrs.  at  the  10  hr.  rate. 

Temperature  and  Charging  Rate — In  determining  the  rate  of  charge  for  the  average  battery,  it  is 
customary  to  take  1/10  of  the  amp.  hr.  capacity,  or  if  this  is  not  available,  one  (1)  ampere  for  each 
pos.  plate  in  a cell.  Where  batteries  of  different  capacities  are  connected  in  series  the  rate  for  the 
smallest  battery  should  be  used. 

In  case  the  temperature  should  rise  about  100°  F.,  frequent  observation  should  be  made.  If  the 
temperature  rises  above  105°  F.,  disconnect  until  the  thermometer  shows  less  than  90°  F.  A sul- 
phated  battery  generally  heats  up  on  charge.  Many  times  this  is  the  first  indication  that  the  battery 


Copyright  1922,  B.  B.  Burling 
Bruce,  Milwaukee,  Publishers 


Loose  Leaf  Shop  Manual 
Burling  Vocational  Series 
Battery  Testing  and  Repair 


is  in  a dangerous  condition.  After  all  cells  are  gassing  freely  at  the  10  hr.  rate,  but  the  acid  is  still  low, 
reduce  to  y2  the  10  hr.  rate,  and  continue  until  fully  charged. 

Sulphated  Battery — In  case  the  battery  is  sulphated  badly,  and  the  temperature  again  rises  to 
about  100°  F.,  reduce  the  charging  rate  to  1/20  of  the  ampere  hour  capacity,  and  continue  until  all 
indications  point  to  a complete  charge.  If  the  battery  still  is  sulphated  discharge  down  to  1.8  volts 
and  charge  again.  Beware  of  patented  preparations  to  reduce  the  sulphate. 

Explosive  Gas — During  charge  never  “spark”  a battery,  as  is  so  often  done  by  inexperienced 
men,  by  snapping  a short  circuiting  wire  across  the  terminals  to  see  if  the  battery  has  “lots  of  pep.” 
The  gasses  inside  the  cell  are  explosive  and  disastrous  results  are  likely  to  follow  such  methods  of 
testing.  For  this  same  reason  never  bring  an  exposed  flame  near  the  vent.  In  case  a flame  is  needed 
for  repairs  on  the  battery  remove  from  charging  line  and  blow  into  the  vent  holes  to  remove  the 
gasses  before  proceeding. 

Conditions  at  Full  Charge — In  determining  whether  a battery  is  fully  charged,  (1)  All  cells  should 
be  gassing  uniformly  at  the  low  rate,  (2)  The  gravity  of  all  cells  should  remain  constant  for  a period 
of  at  least  two  hours,  (3)  In  the  fall  of  the  year  the  acid  strength  should  be  equalized  to  1.280-1.300, 
(4)  The  voltage  of  all  cells  should  be  equal  and  over  2.5  while  on  charge.  Different  makes  of  batteries 
have  different  back  voltage  on  charge.  This  and  the  back  pressure,  due  to  sulphation,  makes  the 
voltage  by  itself  very  unreliable. 


Copyright  1922.  B.  B.  Burling 
Bruce.  Milwaukee.  Publishers 


Loose  Leaf  Shop  Manual 
Burling  Vocational  Series 
Battery  Testing  and  Repair 


Job  A-10— COMPLETE  TEST  OF  SIX-VOLT  STORAGE  BATTERY  (VOLTMETER  AND 

HYDROMETER) 

Object — To  make  a discharge  and  charge  test  on  a storage  battery. 

Apparatus — Lead  storage  battery  previously  charged,  ammeter,  voltmeter,  hydrometer,  adjustable 
resistance  and  source  of  D.  C.  power. 

Method 

1.  Wire  up  the  battery,  ammeter,  voltmeter  and  resistance  for  the  discharge  test  and  take  open 
circuit  voltage  and  hydrometer  readings  on  each  cell. 

2.  Discharge  the  battery  at  either  the  1 or  3 hour  rate  until  the  voltage  has  dropped  to  1.7  in  the 
lowest  cell.  During  this  discharge  take  readings  of  terminal  voltage  and  hydrometer  at  intervals  of 
five  or  ten  minutes  depending  on  the  rate. 

3.  When  the  terminal  voltage  of  1.7  is  reached  quickly  reconnect  for  the  charge  at  the  same  rate. 
Take  readings  at  the  same  intervals  as  in  discharge.  Continue  the  charge  until  the  gravity  ceases  to 

change.  Be  careful  of  temperature. 

4.  Plot  the  curves  of  voltage  vs.  time  and  specific  gravity  vs.  time  for  the  discharge  and  charge. 
(Use  time  on  horizontal). 

5.  Tabulate  all  observations  carefully. 

6.  Mark  on  the  curves  the  point  at  which  “gassing”  appeared. 

Questions 

1.  How  is  the  state  of  discharge  determined? 

2.  How  is  the  state  of  charge  determined? 

3.  What  is  the  highest  and  lowest  voltage  reading  on  discharge? 

4.  What  is  the  highest  and  lowest  voltage  reading  on  charge? 

5.  What  is  the  highest  and  lowest  gravity  reading  on  discharge? 

6.  What  is  the  highest  and  lowest  gravity  reading  on  charge? 

7.  What  is  the  gravity  at  discharge? 

8.  What  charging  voltage  must  be  used  for  a six  volt  battery? 

9.  How  many  six  volt  batteries  can  be  charged  in  series  on  110  volts? 

10.  Explain  what  should  be  done  if  gravity  is  low? 

11.  Explain  what  should  be  done  if  gravity  is  high? 

12.  What  would  cause  gravity  to  be  too  low? 

13.  What  would  cause  gravity  to  be  too  high? 

14.  What  four  things  influence  the  voltage  of  a battery  in  service? 

15.  How  long  will  it  take  to  charge  a 120  a.  h.  battery  at  the  ten  ampere  rate 

16.  What  will  be  the  cost  of  charging  a six  volt  120  a.  h.  battery  at  ten  cents  per  kilo-watt  hour? 

(a)  If  the  110  volt  charging  circuit  is  loaded  to  capacity? 

(b)  If  only  one  six  volt  120  a.  h.  battery  was  on  the  circuit? 

17.  If  no  meters  or  testing  apparatus  are  available  explain  method  of  charge. 


Theory — In  determing  the  rate  of  charge  or  discharge,  other  than  the  eight  or  ten  hour  rate,  the 
following  rule  will  be  found  commercially  accurate. 


Rule:  In  doubling  the  rate  in  amperes  the  time  will  be  reduced  to  1/3. 


Example : 


Rate  in  Amp. 


10 

2x10  or  20 
2 x 20  or  40 
2 x 40  or  80 
2 x 80  or  160 


Discharge  in  Hrs. 

10 

1/3  of  10  or  3 1/3 
1/3  of  3 1/3  or  1 + 

1/3  of  1 or  20  min. 

1/3  of  20  min.  or  7 min. 


It  is  not  always  possible  to  test  a battery  at  its  normal  eight  or  ten  hour  rates.  From  the  name 
plate  information  other  rates  may  be  calculated  and  the  length  of  discharge  approximated. 


Copyright  1922,  B.  B.  Burling 
Bruce.  Milwaukee,  Publishers 


Loose  Leaf  Shop  Manual 
Burling  Vocational  Series 
Battery  Testing  and  Repair 


It  takes  time  for  acid  to  diffuse  into  the  pores  of  the  plates  and  aid  in  maintaining  pressure  and  the 
resultant  current  flow.  At  high  rates  of  discharge  this  lack  of  diffusion  causes  the  loss  in  capacity 
noticed  above.  This  also  explains  how  a battery  may  deliver  100-200  amperes  to  turn  an  engine  over 
and  be  “dead”  in  a few  minutes,  yet  after  a few  moments’  rest  will  appear  to  have  regained  most  of  its 
original  vigor.  In  testing  any  battery  calculate  the  rate  which  will  leave  ample  time  for  recharging. 
Never  permit  a battery  to  remain  long  in  a discharged  condition.  Sulphation  will  result.  Sulphation 
chokes  the  cell  making  it  practically  useless  until  it  can  be  restored  to  its  normal  state. 

The  end  voltage  permissible  at  the  1 and  3 hour  rates  is  1.7  volts,  while  at  lower  rates  of  dis- 
charge 1.8  volts  is  standard.  At  higher  rates  even  lower  end  voltages  are  used.  These  rates,  however, 
are  not  generally  used  in  testing  the  portable  type  of  battery. 

During  discharge  the  acid  gets  weaker  because  of  the  uniting  of  the  sulphate  in  the  electrolyte 
with  the  active  material  in  the  plates.  This  sulphation  is  not  dangerous  if  not  permitted  to  continue 
some  time  before  recharging. 

During  the  charging  process  the  sulphate  in  the  plates  is  transposed  back  to  the  solution.  It  is 
only  when  all  the  sulphate  has  been  transferred  that  the  gravity  ceases  to  rise.  The  following  formula 
is  the  chemical  method  of  expressing  this  transfer  of  sulphate  from  the  solution  to  the  plates  during 
discharge  and  the  transfer  back  during  charge. 

PbO*  + 2H.SO.  + Pb  = PbSO«  + 2PLO  + PbSO< 

Discharge 

c Charge 


Copyright  1922,  B.  B.  Burling 
Bruce,  Milwaukee,  Publishers 


L,oose  Leaf  Shop  Manual 
Burling  Vocational  Series 
Battery  Testing  and  Repair 


Job  A-ll— AMPERE-HOUR  AND  WATT-HOUR  CAPACITIES  AT  DIFFERENT  RATES 

Object — To  become  familiar  with  the  behavior  of  a battery  at  different  rates  of  discharge  and 
charge. 

Apparatus — Six  volt  storage  battery,  heavy  cable  and  regulating  rheostat,  voltmeter,  hydrometer 
and  ammeter  of  200  amp.  range.  * 

Method 

1.  From  the  name  plate  calculate  the  different  rates  as  indicated  in  Job  A-10,  and  if  possible  run 
discharge  and  charge  tests  at  the  8,  3,  1,  and  1/3  hour  rates. 

2.  From  the  data  obtained  compute  the  amp.  hr.  capacities  and  plot  a.  h.  capacity  vs.  rate. 

3.  If  the  voltage  readings  are  at  equal  intervals  average  the  readings  to  get  average  voltage 
of  charge  or  discharge. 

Multiply  this  voltage  by  the  current  rate  of  discharge  and  by  the  time  to  get  the  watt-hr.  capacity. 
Watt  hour  = average  voltage  X current  X time  in  hours.  Plot  the  watt-hr.  capacity  vs.  rate  of  dis- 
charge. In  case  the  voltage  readings  are  infrequent  or  irregular,  plot  the  voltage-time  curve  and  from 
this  curve  determine  the  average  reading. 

Questions 

1.  Calculate  the  relationship  which  exists  between  amp.  hr.  capacity  and  rate  of  discharge. 

2.  Calculate  the  relationship  which  exists  between  the  rate  of  discharge  and  the  time. 

3.  Calculate  the  relationship  which  exists  between  the  watt-hour  capacity  and  rate  of  discharge. 

4.  From  the  curves  drawn  calculate  the  ampere  hour  capacity  at  the  five  amp.  rate. 

5.  Calculate  the  ampere  hour  capacity  at  the  20  min.  rate. 

6.  Calculate  the  ampere  hour  input  at  the  8,  3,  1,  1/3  hr.  rates.  Figure  the  end  of  charge  at 
the  point  where  the  gravity  ceases  to  rise. 

7.  Why  is  the  ampere  hour  capacity  not  changed  by  adding  cells  in  series  but  is  increased  when 
cells  are  connected  in  parallel? 

8.  How  will  the  area  of  a plate  affect  its  available  capacity?  Why? 

9.  How  will  the  thickness  of  a plate  affect  its  available  capacity?  Why? 

10.  How  will  the  temperature  of  a battery  affect  its  available  capacity?  Why? 

11.  Why  will  the  rate  of  discharge  affect  the  capacity? 

12.  What  effect  has  service  on  ampere  hour  capacity?  Why? 

13.  How  will  the  watt-hour  capacity  be  changed  by  adding  cells  in  series?  Why? 

Theory — From  the  tests  it  is  evident  that  the  ampere  hour  capacity  of  a battery  means  nothing 
unless  the  rate  is  also  specified. 

The  Society  of  Automotive  Engineers  has  specified  two  tests  which  are  considered  standard  for 
starting  and  lighting  batteries.  For  lighting  purpose  the  ampere  hour  capacity  is  figured  at  the  five 

ampere  rate  down  to  a voltage  of  1.8.  For  starting  purposes  the  capacity  is  figured  at  the  rate  which 

will  discharge  the  battery  in  20  minutes  down  to  approximately  1.65  volts. 

It  is  somewhat  unfortunate  that  commercially  the  watt-hour  capacity  is  not  the  determining  or 
selling  basis.  It  is  evident  that  an  Edison  battery  might  have  ample  capacity  in  amp.  hrs.  and  still 
be  very  undesirable  for  starting  purposes. 

Various  makes  of  standard  storage  batteries  will  differ  widely  on  the  watt-hour  capacity  and  still 
be  alike  on  the  ampere-hour  basis.  The  nature  of  the  electrolyte,  whether  liquid  or  solid,  high  or  low 
gravity,  effects  the  wattage  output.  In  fact  any  features  of  a cell  which  raise  the  resistance  will 
decrease  the  terminal  voltage  and  the  resultant  watt-hour  capacity. 

The  ampere  hour  capacity  of  a battery  is  dependent  upon : 

1st.  The  weight  of  active  material  in  the  plates. 

2nd.  The  plate  area. 

3rd.  The  thickness  of  the  plates. 

4th.  Temperature. 

5th.  Specific  gravity  of  electrolyte. 

6th.  Previous  conditions  of  service. 

7th.  Rate  of  discharge. 


Copyright  1922,  B.  B.  Burling 
Bruce,  Milwaukee,  Publishers 


nt 


Loose  Leaf  Shop  Manual 
Burling  Vocational  Series 
Battery  Testing  and  Repair 


Job  A-12— STORAGE  BATTERY  EFFICIENCY 

Object — To  become  familiar  with  the  efficiency  of  standard  makes  of  lead  storage  batteries,  and 
also  the  ampere  hour  and  watt  hour  capacity  per  pound  of  cell. 

Apparatus — Six  volt  storage  battery  different  from  the  one  used  in  Job  A-ll,  voltmeter,  ammeter 
200  range,  hydrometer  and  regulating  resistance. 

Method 

1.  Obtain  the  discharge  and  charge  data  at  the  five  ampere  and  the  20  minute 

2.  Calculate  the  ampere  hour  input  and  output  from  the  data  obtained. 

3.  Calculate  the  watt  hour  input  and  output  from  the  data  obtained. 

4.  Calculate  the  ampere  hour  efficiency  (output  H- input  = eff.),  and  the  watt 
the  two  standard  rates. 

Ampere  hour  output  on  discharge 

= Ampere  hour  efficiency. 

Ampere  hour  input  on  charge 

Watt  hour  output  on  discharge 

= Watt  hour  efficiency. 

Watt  hour  input  on  charge 

5.  Compare  these  efficiencies  with  the  efficiencies  obtained  from  data  in  Job  A-ll. 

6.  Weigh  both  batteries  and  calculate  the  watt  hour  and  amp.  hour  capacity  per  pound  of  battery 
weight. 

Questions 

1.  Is  the  heavier  battery  the  safest  to  buy?  Why? 

2.  Where  would  you  look  for  a decrease  in  weight  without  loss  in  length  of  service? 

3.  Is  the  battery  with  highest  watt  hour  or  ampere  hour  efficiency  always  the  safest  to  buy? 
Why? 

4.  What  points  would  govern  your  selection  of  a battery  for  personal  use?  For  selling? 

5.  Does  1.300  acid  always  indicate  complete  charge?  Why? 

6.  Does  two  volt  per  cell  of  an  idle  battery  indicate  complete  charge?  Why? 

7.  Can  you  expect  the  same  mileage  from  an  electric  vehicle  in  winter  as  in  summer?  Why? 

8.  Is  2.55  volts  an  indication  of  complete  charge?  Why? 

9.  What  rule  would  you  suggest  in  determining  the  state  of  charge  of  a battery? 

Theory — There  are  two  distinct  types  of  batteries  in  general  use  although  both  are  not  adaptable 
for  starting  and  lighting.  I.  The  lead  battery  whose  plates  are  made  up  either  of  pasted  grid  or  solid 
lead  has  a voltage  of  approximately  two  per  cell  and  is  capable  of  extremely  high  discharge  rates. 
II.  The  Nickel-Iron  cell  whose  plates  are  composed  of  nickled  iron  grid  or  holder  with  nickel  oxide 
and  flake  nickel  as  the  active  elements  has  a voltage  of  about  1.25,  but  the  high  interval  resistance  pre- 
vents high  discharge  rates.  Both  types  have  their  distinctive  advantages  for  particular  classes  of 
service. 

Of  the  lead  type,  which  is  the  most  common,  there  are  two  divisions.  The  Plante  or  solid  formed 
lead  plate  has  the  advantages  which  makes  it  serviceable  for  a stationary  battery  where  life,  weight 
and  space  are  not  sacrificed  for  portability.  The  Faure  or  pasted  class  of  battery  plate  is  extremely 
efficient  from  the  standpoint  of  capacity  per  pound  of  cell,  although  life,  weight  and  space  are  sacri- 
ficed in  order  to  produce  a battery  suitable  for  the  service  desired  in  automobile  work. 


rates. 

hour  efficiency  at 


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Bruce.  Milwaukee,  Publishers 


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Loose  Leaf  Shop  Manual 
Burling  Vocational  Series 
Battery  Testing  and  Repair 


Job  A-13— CURB  SERVICE  INSTRUCTION  SHEET 

Object — To  determine  object  of  “curb  service”  and  the  assistance  to  be  rendered  the  car  owner. 

Apparatus — (Equipment  for  curb  service).  Voltmeter  0-3-15  range,  high  rate  discharge  tester, 
distilled  water,  hydrometer,  grease  or  vaseline,  soda  solution,  several  used  batteries. 

Method 

1.  Test  gravity  of  acid  of  a used  battery.  Make  recommendations  (to  owner)  as  to  freezing, 
temperature  of  battery,  when  to  come  for  acid  equalization. 

2.  Fill  with  distilled  water.  Make  recommendations  (to  owner)  as  to  filling,  frequency  of  serv- 
ice, height  of  electrolyte,  when  to  fill  in  cold  weather. 

3.  If  battery  is  reported  as  giving  trouble  and  gravity  tests  O.  K.,  or  if  electrolyte  is  so  low 
that  no  test  can  be  made,  test  each  cell  with  “high  rate”  tester  and  voltmeter.  Make  recommenda- 
tions (to  owner)  as  to  apparent  repairs  necessary. 

4.  Should  repairs  be  necessary  detain  owner  while  a “loaner”  is  installed.  Helper  opens  cell 
for  immediate  inspection.  Cost  of  repair  is  given.  State  time  required  for  repair. 

5.  Should  repairs  be  uncertain,  make  recommendations  about  the  bench  charge,  test,  etc.  Install 
“loaner.” 

6.  If  battery  is  O.  K.  brush  off  dust,  brush  with  soda  solution  to  neutralize  any  acid  on  top  of 
cells  and  corrosion  at  terminals.  Wipe  dry  and  cover  terminals  with  grease  or  vaseline.  Make  recom- 
mendations as  to  proper  care  to  avoid  like  conditions  in  the  future. 

Note:  Report  in  detail  the  recommendations  which  would  be  made  to  owner  in  each  of  the  above 
tests. 


Questions 

1.  What  trouble  may  result  from  corroded  terminals? 

2.  How  would  you  determine  whether  the  terminals  are  corroded? 

3.  Which  terminal  seems  to  be  corroded  the  more? 

4.  What  is  liable  to  result  if  the  battery  is  not  secured  in  position? 

5.  If  the  lighting  and  ignition  seems  O.  K.,  but  the  motor  cannot  turn  the  engine  over,  what 
trouble  may  be  located  in  the  battery? 

6.  If  lights  will  not  burn,  what  trouble  may  be  located  in  the  battery? 

7.  What  care  should  be  used  with  tools  around  a battery?  Why? 

8.  How  should  water  be  added  to  a battery?  Explain  in  detail. 

9.  What  will  result  if  soda  solution  gets  inside  of  cells? 

10.  Why  is  periodic  inspection  advocated  by  all  manufacturers?  1 

11.  If  battery  is  low  why  is  it  generally  advisable  to  remove  battery  from  car  to  recharge  it? 


Theory — The  object  of  “curb  service”  is  to  keep  in  close  touch  with  battery  owners.  Real  service 
along  the  lines  suggested  will  bring  reward.  Customers  will  be  held  and  new  ones  obtained. 

Curb  service  is  the  connecting  link  between  the  firm  and  the  future  and  past  customer. 

Curb  service  is  generally  used  to  mean  “watering  a battery”  but  occasionally  acid  is  added.  This 
is  a dangerous  practice.  Wherever  possible  get  the  battery  in  the  shop  for  24  hours  charge  and 
equalization. 

Be  careful  not  to  transfer  acid  from  one  cell  to  another  when  testing  gravity. 

It  is  always  advisable  to  record  the  gravity  readings  in  a manner  that  will  indicate  the  general 
condition  of  each  cell  when  the  customer  again  calls  for  service.  It  is  unnecessary  to  keep  this  record 
at  the  service  station,  but  it  should  be  recorded  on  the  battery  box,  floor  board  of  car,  or  any  pro- 
tected place  on  the  car  near  the  battery.  Any  marking  systems  would  be  suitable  but  the  following 
methods  are  suggested.  Numbers  are  preferable. 


1.260  —4 
1.265  —3 
1.270  —2 
1.275  —1 

1 .280  no  mark  or  0 
1.285  +1 

1.290  +2 

1.295  +3 

1.300  +4 

Should  all  indications  show  that  the  battery  is  O.  K.,  advise  the  owner  to  disconnect  the  battery 
at  the  end  of  a run.  best  the  gravity  and  again  the  next  day  before  starting  out.  This  will  clearly 
indicate  whether  the  fault  is  in  the  wiring  or  inside  the  battery. 


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Bruce.  Milwaukee,  Publishers 


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Loose  Leaf  Shop  Manual 
Burling  Vocational  Series 
Battery  Testing  and  Repair 


job  A-14— BATTERY  DIAGNOSIS  PRIOR  TO  OPENING  UP 

Object — To  become  familiar  with  the  ear  marks  of  defects  without  opening  the  battery. 

Apparatus — High  rate  discharge  tester,  hydrometer,  voltmeter  0-3-15  range,  charging  apparatus  and 
six  volt  battery  giving  trouble. 

Method 

1.  Place  the  battery  on  charge  at  the  normal  rate. 

2.  Watch  the  gravity  closely  in  the  separate  cells.  Record  these  and  voltmeter  readings,  noting 

any  increasing  difference.  The  cell  which  is  “slow  to  come  up”  should  be  regarded  with  suspicion. 

3.  Charge  until  the  gravity  ceases  to  rise,  even  though  the  gravity  is  not  the  same  in  all  cells. 

Open  the  circuit  and  test  with  a voltmeter.  Repeat  at  fifteen  minute  intervals,  taking  also  gravity 
readings  for  one  hour,  or  until  the  condition  of  the  battery  is  determined. 

4.  In  case  of  doubt  or  as  additional  check,  take  a “high  rate  test”  using  tester  made  for  this  pur- 
pose. If  there  is  a variation  of  .1  volt  or  more  per  cell  it  indicates  that  the  low  cell  is  defective. 

5.  If  tests  show  cells  in  good  condition  equalize  acid,  wash  outside  of  box  with  soda,  and  place 
in  clean  place  to  note  if  any  of  the  jars  are  leaky.  Continue  the  charge  to  thoroughly  mix  the  electro- 
lyte. Charge  for  at  last  five  hours  at  one-half  normal  rate  to  insure  reduction  of  sulphate  and  mixing 
of  electrolyte. 

Questions 

1.  Before  removing  a battery  from  a car,  what  should  be  done? 

2.  Why  is  it  necessary  to  fill  cells  with  distilled  water  before  charging? 

3.  If  all  terminal  markings  are  removed  how  would  you  determine  the  polarity  ? Two  or  three 
methods. 

4.  How  would  you  test  for  a broken  terminal 

Theory — The  hydrometer  diagnosis  is  by  far  the  most  suitable  for  unskilled  help  although  the  car 
owner  may  note  various  symptoms  of  a “sick”  battery,  namely : 

1.  Lamps  not  bright. 

2.  Horn  not  so  loud  as  usual. 

3.  Lamps  burn  dimly  after  being  on  some  time. 

4.  Motor  turns  engine  over  slowly  or  not  at  all. 

The  causes  of  low  gravity  are  several : 

1.  Internal  short  due  to  accumulated  sediment  or  broken  separators. 

2.  External  short  circuit  in  the  wiring  system  of  the  car. 

3.  Leaky  jars. 

4.  Sulphation. 

The  preliminary  tests  are  to  determine  whether  the  cause  of  low  gravity  is  internal  or  external. 
It  is  assumed  that  the  owner  has  tested  his  circuits  as  indicated  in  the  “curb  service.” 

In  making  all  hydrometer  tests  remember  that  the  middle  cell  is  likely  to  show  a lower  gravity 
because  of  higher  temperature.  This  cell  will  also  show  “low  acid”  due  to  evaporation  before  the  others. 
Because  of  this,  absolute  uniformity  of  gravity  is  seldom  possible. 

The  variation  in  “gravity”  should  not  exceed  20  points.  Thus,  “gravities”  of  1.285,  1.275,  and 
1.295  in  the  three  cells  respectively  are  sufficiently  uniform  for  practical  purposes.  Under  a cell 
“high  rate”  discharge,  the  cells  should  be  each  discharged  only  a few  seconds.  The  voltage  indicator 
will  generally  show  between  1.4  and  1.6  volts,  depending  on  the  size  of  the  cell.  Each  cell  of  a battery 
should,  however,  indicate  the  same  voltage.  Fig.  8. 

A battery  high  rate  tester  is  also  made  to  test  the  entire  battery.  The  theory  of  this  tester  is 
that  if  any  cell  is  down  the  entire  battery  should  be  overhauled.  It  is  quicker  to  make  a complete  test 
in  one  operation  than  in  three  or  more.  Fig.  9. 

The  illustrations  show  the  two  standard  pieces  of  apparatus  for  high  rate  discharge. 


Fig.  8. 


Copyright  1922,  B.  B.  Burling 
Bruce,  Milwaukee,  Publishers 


Loose  Leaf  Shop  Manual 
Burling  Vocational  Series 
Battery  Testing  and  Repair 


Job  A-15— THE  CADMIUM  TEST  ON  CHARGE  AND  DISCHARGE 

Object — To  become  acquainted  with  the  test  which  is  universally  used  by  manufacturers  to  indi- 
cate the  individual  condition  of  the  pos.  or  neg.  plates. 

Apparatus — Charging  equipment,  voltmeter,  cadmium  stick,  six  volt  battery. 

Method 

1.  See  that  the  battery  is  fully  charged. 

2.  Run  a discharge  test  at  about  the  three  hour  rate  taking  voltage  between  Pos.  and  Cad., 
Neg.  and  Cad.,  and  Pos.  and  Neg.  plates.  Fig.  10. 


Fig.  10. 

3.  Run  a charge  test  taking  like  readings  at  least  every  15  minutes  until  charged. 

4.  Plot  the  voltage  and  cadmium  readings  for  charge  and  discharge. 

5.  Study  the  details  of  the  curves  and  discuss  in  the  write-up  the  condition  of  the  pos.  and  neg. 
groups  of  each  cell. 

Questions 

1.  Could  a cadmium  test  be  used  to  lessen  the  long  over-charge  many  times  resorted  to  in  order 
to  insure  a charged  battery?  Why? 

2.  How  would  you  use  a cadmium  test  to  determine  whether  or  not  the  acid  is  weak  due  to  slop- 
page  or  sulphation  ? 

3.  When  a battery  is  repaired  by  installing  new  positive  groups,  how  could  the  test  be  used  to 
indicate  whether  or  not  the  battery  was  ready  to  be  placed  in  service? 

Theory — Whenever  the  voltage  of  a cell  is  taken,  it  is  self-evident  that  this  reading  includes  the 
condition  of  the  pos.  plates  -f-  the  condition  of  the  neg.  plates.  The  electrochemical  condition  of  the 
plates  we  call  potential.  The  cell  voltage  therefore  becomes  the  pos.  potential  -j-  neg.  potential  or 
pos.  -J-  neg.  voltage.  Cadmium  in  the  commercial  form  has  a potential  or  individual  voltage  of  almost 
zero.  The  voltage  between  this  element  (cadmium)  and  any  other  element  would  naturally  only  indi- 
cate the  potential  of  the  one  inasmuch  as  the  pressure  of  cadmium  is  zero.  The  cadmium  test  is  not 
always  essential  although  there  is  considerable  satisfaction  in  knowing  the  exact  condition  of  the 


Copyright  1922,  B.  B.  Burling 
Bruce.  Milwaukee,  Publishers 


Loose  Leaf  Shop  Manual 
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Battery  Testing  and  Repair 


plates.  The  negative  test  will  invariably  show  where  the  fault  lies,  unless  the  cell  is  shorted.  The 
negative  plate  seems  to  be  more  susceptible  to  sulphation  than  the  positive. 

The  cadmium  stick  should  always  be  kept  wet  so  as  to  insure  reliable  data. 

The  “stick”  is  covered  with  perforated  rubber  so  as  to  insure  against  making  electrical  contact  with 
the  plates  and  still  come  in  contact  with  the  solution.  When  taking  cadmium  readings  insert  the 
“stick”  in  the  vent  so  that  it  will  come  in  contact  with  solution.  (Fig.  10).  From  the  data  taken 
it  will  be  noticed  that  when  the  cell  is  discharged  the  voltages  may  be  represented  by  diagram  II,  while 
when  fully  charged  by  III.  (The  numbers  indicate  the  approximate  conditions  of  a new  cell.) 


Discharged 


-+■  — CD 

-L8 

- a os  - 

II. 


.25 


Charged 


+ CD 


-a.5- 


15 


2 65  - 

III. 


In  II  the  pos.  and  neg.  plates  are  -j-  to  the  cadmium  and  in  III  the  neg.  plate  has  changed  its  rel- 
ative position  and  is  — to  the  cadmium. 

It  will  further  be  noted  that  if  the  neg.  plate  is  -f-  to  the  cadmium  or  close  to  it  in  voltage  the  cell 
should  receive  a longer  charge. 

As  all  voltage  readings  depend  somewhat  upon  the  rate  of  charge  or  discharge,  always  compare 
readings  at  like  rates  of  current. 

Note:  In  all  battery  work  it  must  be  remembered  that  seldom  should  one  test  determine  the  con- 
dition of  the  battery,  but  two  or  more  tests  using  different  methods. 


Copyright  1922,  B.  B.  Burling 
Bruce,  Milwaukee,  Publishers 


Loose  Leaf  Shop  Manual 
Burling  Vocational  Series 
Battery  Testing  and  Repair 


Job  A-16— TESTING  BATTERY  JARS 
Object — To  find  out  different  methods  of  testing  jars  for  “leakers.” 

Apparatus — Several  jars  which  have  proven  defective,  vibrating  spark  coil,  magneto  ringer,  and  110 
volt  lighting  circuit. 

Method 

1.  Strike  several  jars  which  are  defective  and  determine  to  what  extent  a sound  test  can  be  used. 

2.  Fill  a jar  with  water  and  set  in  water.  (Keep  the  top  of  the  jar  dry).  Test  with  magneto 

ringer  with  one  terminal  inside  and  one  outside.  Note  results. 

3.  Try  the  same  test  on  a six  volt  battery  to  detect  a broken  jar.  State  the  advantages  and  dis- 
advantages of  such  a test. 

4.  Repeat  tests  2 and  3 using  a spark  coil  and  battery.  Explain  results. 

5.  Repeat  tests  2 and  3 using  the  lighting  circuit.  Make  connections  as  shown  in  Fig.  11.  Ex- 

plain results. 


Questions 

1.  Which  of  the  above  methods  of  testing  single  jars  proved  the  most  satisfactory?  Why? 

2.  Which  proved  the  most  satisfactory  in  testing  battery  when  assembled?  Why? 

3.  When  a battery  is  in  service  what  conditions  indicate  a broken  jar? 

Theory— It  is  generally  not  difficult  to  locate  a leaky  cell  if  the  cause  has  been  freezing.  Usu- 
ally such  a leak  will  be  sufficient  to  cause  a visible  lowering  of  electrolyte  in  the  jar  and  the  sub- 
sequent moistening  and  rotting  of  the  box. 

The  principle  most  used  in  locating  leaks  is  simply  that  acid  is  conductive.  If  the  cell  has  been 
filled  with  acid  some  of  the  electrolyte  has  penetrated  the  jar  through  the  crack.  This  thread  of 
moisture  is  a sufficiently  good  conductor  to  permit  satisfactory  testing  on  the  lighting  circuit.  Manu- 
facturers usually  detect  a crack  by  the  sound  when  the  jar  is  struck.  This  is  probably  accurate 
enough  from  their  standpoint,  but  this  method  will  not  detect  a pin  hole  leak. 

No  test,  no  matter  how  good,  will  take  the  place  of  observation  of  conditions.  The  tests  should  be 
used  as  a last  resort  when  observation  has  failed. 

It  would  be  advisable  to  have  a suitable  testing  method  or  device  in  every  station  and  not  rely 
entirely  on  observation. 


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Bruce,  Milwaukee,  Publishers 


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Loose  Leaf  Shop  Manual 
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Job  A-17-  HOW  TO  OPEN  A LEAD  STORAGE  BATTERY 

Object — To  find  out  the  different  methods  used  at  service  stations  in  opening  up  a storage  battery. 

Apparatus — Two  six  volt  batteries  of  different  makes,  brace  and  bits,  steamer,  heated  putty 
knife,  and  brush. 

Method — (Note  the  time  required  to  perform  the  operations  of  opening  a cell). 

1.  Clean  the  top  of  the  battery  with  a stiff  brush.  Use  water  or  gasoline  if  necessary.  Vents 
must  be  closed. 

2.  Make  a sketch  of  the  strap  connections  on  a tag  and  fasten  same  to  handle. 

3.  Drill  through  the  connector  straps  as  indicated  in  Fig.  12.  It  is  better  to  do  this  work  with 
the  battery  on  a low  bench  and  in  a tray  to  collect  all  the  lead  chips.  See  Fig.  13  and  Fig.  14. 

4.  Remove  connector  straps  as  indicated  in  Fig.  15  being  careful  not  to  injure  jars  or  wooden  case. 


Fig.  16. 

Copyright  1922,  B.  B.  Burling 
Bruce,  Milwaukee,  Publishers 


; . Ill 

Fig.  12.  1 

Fig.  13.  Fig.  14. 

5.  Place  in  steamer  as  shown  in  Fig.  16  until  the  sealing  compound  has  softened.  If  necessary, 
heat  the  putty  knife  and  loosen  the  sealing  compound  one  cell  at  a time. 

6.  Try  the  putty  knife  without  steaming. 


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7.  Hold  the  battery  in  “floor  clamp”  Fig.  18  and  with  the  aid  of  two  pliers  or  tongs  raise  element 
and  drain.  See  Fig.  17  for  correct  position  when  raising  element.  Remove  cover,  Fig.  19. 

8.  Permit  the  elements  to  drain  a few  minutes.  Fig.  20. 


Fig.  17. 


Fig.  18. 


Fig.  20. 


Theory — Among  the  commercial  methods  used  in  opening  batteries  are  the  following: 

1.  The  use  of  a hot  knife  to  loosen  the  sealing  compound.  This  method  is  effective  when  only 
a small  quantity  of  compound  is  used. 

2.  Hot  running  water  run  into  the  vents  until  the  compound  is  softened  sufficiently.  Although 
not  a rapid  method  is  satisfactory  where  large  quantities  of  water  are  available. 

3.  Steam  run  into  the  cells  through  the  vents  is  a popular  method  and  probably  the  best  for 
the  average  service  station  where  all  varieties  of  cells  are  repaired. 

4.  External  heating  by  flame  is  not  as  satisfactory  because  the  flame  burns  the  compound  giving 
off  black  smoke  and  does  not  heat  uniformly. 

5.  External  heating  in  an  oven  has  the  disadvantage  of  cost  if  an  electric  oven,  and  difficulty  of 
knowing  when  the  compound  is  softened  sufficiently. 

Note:  Never  try  to  pound  the  terminals  loose  as  such  rough  treatment  is  sure  to  weaken  the 
connection  between  plates  and  connecting  strap  and  between  active  material  and  the  plates.  If  ter- 
minals cannot  be  easily  removed  drill  through  and  soak  in  soda  water. 

It  is  always  considered  wise  to  have  the  owner  present  when  the  battery  is  opened. 


Copyright  1922,  B.  B.  Burling 
Bruce.  Milwaukee.  Publishers 


Loose  Leaf  Shop  Manual 
Burling  Vocational  Series 
Battery  Testing  and  Repair 


Job  A-18— WINTER  STORAGE 

Object — The  object  of  the  test  is  to  become  familiar  with  different  methods  of  storing  a battery. 
Apparatus — One  or  two  six  volt  storage  batteries,  suitable  means  of  charging. 

Method 

In  order  to  become  familiar  with  the  various  methods  of  storage,  the  battery  should  be  opened  and 
each  cell  tested  differently.  The  value  of  this  method  is  two-fold.  The  test  will  show  a comparison 
of  the  different  ways  of  storage  as  no  other  test  can  and  also  the  detailed  method  of  procedure  in  each 
case. 

1.  Charge  the  batteries  until  fully  charged. 

2.  Open  up  the  battery  and  prepare  one  cell  for  storage  by  method  No.  2 (wet  storage).  (See 
Theory). 

3.  Prepare  one  cell  for  storage  by  wet  method  No.  3. 

4.  Prepare  one  cell  for  storage  by  dry  method  No.  1. 

5.  Prepare  one  cell  for  storage  by  dry  method  No.  2. 

6.  Reassemble  the  cells  after  the  plates  are  dry.  Charge  in  series  keeping  close  watch  on  tem- 

perature, gravity  and  voltage. 

Questions 

1.  Which  method  of  wet  storage  brought  the  plates  back  quicker?  Explain  all  details  of  test. 

2.  Which  method  of  dry  .storage  kept  the  plates  in  best  condition? 

3.  Which  group  of  negatives  heated  the  most? 

4.  Which  method  of  dry  storage  brought  the  cells  up  to  charge  in  the  shortest  time? 

Theory— Storage  is  necessary  when  the  auto,  is  to  be  laid  up  for  some  time  especially  in  the 
winter.  A battery  gradually  discharges  and  is  liable  to  freeze  if  neglected. 

How  to  store  a battery,  and  how  to  determine  which  method  to  use,  are  questions  which  always 
arise. 

In  general,  dry  storage  should  be  used  when  a battery  in  all  probability  will  require  attention  in  a 
short  time,  or  if  it  is  to  be  left  in  storage  for  three  or  more  months.  Wet  storage  is  less  costly  and  is 
generally  used.  (Use  high  rate  test  to  determine  condition  of  battery  before  deciding  on  the  method 
to  use). 

Wet  Storage 

No.  1 (a)  Charge,  (b)  Place  on  rack  with  instructions  to  give  a freshening  charge  every  month. 
(Keep  gravity  up  to  normal). 

No.  2 (a)  Charge,  (b)  Empty  out  acid,  (c)  Wash  out  sediment,  (d)  Fill  with  fresh  water, 
(e)  Place  on  shelf  until  needed,  (f)  When  needed  a bench  charge  is  necessary  after  filling  with  1.310 
acid. 

No.  3 (a)  Charge,  (b)  Empty  out  acid,  (c.)  Wash  out  sediment,  (d)  Place  in  cool  place 
until  needed,  (e)  When  needed  fill  with  1.300  acid  and  charge. 

No.  4 (a)  Charge  on  bench  until  fully  charged,  (b)  Place  on  storage  bench  where  the  battery  is 
connected  in  series  with  others  and  the  charge  continued  at  .1  amp.  continuously  until  needed.  In  order 
to  regulate  the  current  connect  incandescent  lamps  in  series  with  the  battery. 

Note:  Of  these  methods  probably  No.  4 is  the  best  where  suitable  D.  C.  is  available  because  less 
handling  is  necessary  and  the  battery  can  be  had  on  short  notice.  Method  No.  2 has  many  points  in 
its  favor  and  is  better  than  No.  1 or  No.  3.  In  all  acid  storage  fill  with  water  every  two  months. 

Dry  Storage 

No.  1 charge,  open  up  battery,  take  out  elements,  separate  groups  if  possible,  and  set  in  water 
over  night,  set  groups  out  to  dry.  When  negative  group  heats,  dip  in  water  and  set  out  again  to  dry. 
In  reassembling  use  new  separators  and  charge  at  one-half  normal  rate. 

No.  2 charge,  open  up  battery,  empty  out  acid,  fill  with  water,  let  stand  over  night,  empty  and  fill 
with  fresh  water,  short  circuit  the  battery  for  one  hour,  remove  the  groups  to  dry.  In  reassembling  use 
new  separators  and  charge  at  one-half  normal  rate. 

Note:  In  disassembling  a battery  always  make  a sketch  in  chalk  on  the  box  or  on  a tag  showing 
detail  of  strap  connection. 


Copyright  1922,  B.  B.  Burling 
Bruce,  Milwaukee,  Publishers 


& i^ir 


a 


Loose  Leaf  Shop  Manual 
Burling  Vocational  Series 
Battery  Testing  and  Repair 


Job  A-19— MINOR  DEFECTS  AND  REPAIRS 

Object — To  take  care  of  repairs  which  will  require  little  time  and  expense.  (24  hours  service). 
Repairs  which  do  not  involve  the  plates. 

Apparatus — Battery  with  broken  jar,  battery  requiring  new  separators,  corroded  terminals. 

Method 

1.  Fill  the  jar  which  is  to  be  removed  with  boiling  hot  water  and  allow  to  stand  about  five 
minutes.  Remove  the  jar  as  shown  in  Fig.  21. 

2.  Fill  the  new  jar  with  boiling  hot  water  at  the  same  time  the  old  jar  was  filled.  The  rubber 
will  be  soft  and  pliable  when  ready.  A flame  is  sometimes  played  on  the  outside  of  the  jar  instead 
of  using  hot  water.  The  only  possible  disadvantage  of  this  method  is  that  the  jar  is  not  usually  heated 
uniformly. 


Fig.  21. 

3.  Replace  the  old  jar  after  the  inside  of  the  box  has  been  oiled  with  vaseline  and  the  jar  warmed. 

4.  In  replacing  separators  care  should  be  taken  that  the  grooved  side  is  against  the  pos.  plate. 
The  circulation  which  this  will  bring  to  the  surface  of  the  pos.  plate  will  increase  the  life  by  remov- 
ing any  organic  acid  present  in  the  wood. 

5.  Wash  all  corroded  terminals  and  place  all  loose  parts  in  soda  water  until  clean. 

Questions 

1.  What  instructions  would  you  give  to  a battery  owner  in  order  to  avoid  the  external  defects 
noted  ? 


Copyright  1022,  B B Burling 
Bruce,  Milwaukee,  Publishers 


Loose  Leaf  Shop  Manual 
Burling  Vocational  Series 
Battery  Testing  and  Repair 


2.  What  instructions  would  you  suggest  to  avoid  the  occurrence  of  the  internal  defects? 

3.  What  causes  a terminal  to  break  off? 

4.  Under  what  conditions  can  the  repairs  be  taken  care  of  away  from  the  service  station? 

5.  Under  what  conditions  should  a battery  be  sent  to  a service  station? 

Theory — The  vital  part  of  any  storage  battery  is  the  plates.  Troubles  located  in  or  vitally  effect- 
ing these  vital  organs  will  be  handled  later.  Minor  defects  are  considered  as  all  troubles  which  occur 
externally  and  internally,  still  not  materially  affecting  the  plates. 

External  defects  are  caused  largely  by  improper  watering  cells.  Over  flooding  will  start  cor- 
rosion of  terminals,  rotting  of  box,  and  eating  away  of  the  metal  parts  of  the  car  surrounding  the 
battery.  These  defects  are  of  minor  importance  if  their  influence  is  not  extended  to  the  inside  of  the 
cell.  In  order  to  avoid  such  danger,  frequent  watering  and  not  too  much  at  any  one  time  should 
be  the  policy. 

Corroded  terminals  may  be  avoided  by  coating  the  top  of  the  battery  and  terminals  with  vase- 
line. Should  they  become  corroded  wash  off  with  solution  of  washing  or  baking  soda.  Many  times 
cable  terminals  which  cannot  be  easily  removed  can  be  loosened  in  a few  minutes  by  applying  soda 
water. 

Acid  soaked  boxes  should  be  so  treated  with  soda  and  when  dry  coated  with  acid  proof  paint. 

Internal  Minor  Defects — Separators  of  wood  must  be  treated  to  remove  injurious  organic  chemicals 
from  the  fiber.  Many  such  organic  substances  are  oxydizing  agents  and  when  present  in  a cell  eat 
away  the  lugs,  grids,  and  connecting  straps  of  the  positive  group.  Any  cell  which  shows  such  corrosion 
is  evidence  that  “raw”  or  improperly  treated  separators  were  used  when  the  cell  was  last  assembled. 
Whenever  new  separators  are  added  to  a cell  and  foaming  is  noticed  on  charge,  it  is  evident  that  the 
“curing”  has  not  been  thorough.  Under  such  circumstances  empty  out  the  acid  at  the  end  of  the 
charge  and  replace  with  fresh  electrolyte.  This  precaution  should  prolong  the  life  of  the  battery  con- 
siderably. The  separator  is  the  weakest  part  of  the  cell  and  it  is  important  that  good  reliable  ones 
are  used  in  any  repair  work. 

Separators  fail  because  of  heating,  strong  acid,  and  buckling  of  pos.  plates. 

Hard  wood  or  rubber  costs  more  than  bass  wood  and  also  offers  a greater  resistance  to  the  elec- 
tric current,  but  the  prolonged  life  of  the  cell  will  more  than  repay  for  the  additional  cost. 

In  all  repairs  where  the  plates  are  exposed  to  the  air,  the  work  should  be  done  as  quickly  as 
possible  as  drying  will  heat  and  injure  the  negative  plates. 

Should  the  plates  require  attention  the  policy  is  generally  to  separate  the  plates  if  shorted  and 
then  place  on  charge  until  the  plates  are  in  normal  condition.  This  will  soften  the  material  and  per- 
mit pressing  if  need  be. 


Fig.  22. 

In  case  only  one  cell  is  to  be  inspected,  drill  through  the  connectors  at  the  ends  farthest  from  the 
cell  to  be  opened.  If  the  middle  cell  is  to  be  inspected,  drill  into  terminal  posts  marked  X,  Fig.  22. 
This  method  is  always  desirable  because  a complete  inspection  of  a six  volt  battery  can  be  made  with 
only  two  drillings. 


Copyright  1922,  B.  B.  Burling 
Bruce,  Milwaukee,  Publishers 


Loose  Leaf  Shop  Manual 
Burling  Vocational  Series 
Battery  Testing  and  Repair 


Job  A-20— LEAD  BURNING 

Object — To  learn  the  methods  used  in  welding  lead  to  lead. 
Apparatus — One  or  more  of  the  following  apparatus : 

1.  Oxygen  and  Acetylene. 

2.  Hydrogen  and  Oxygen. 

3.  Illuminating  gas  and  oxygen. 

4.  Electrical  A.  C.  low  voltage. 

5.  Electrical  D.  C.  low  voltage. 

6.  Soldering  flux  (non-corrosive). 


r~i  i. < 

< — w 


^ 1 1 

Fig.  24. 


1.  Examine  each  piece  of  apparatus  (Fig.  26)  carefully  before  lighting  flame. 

2.  When  confident  of  knowing  the  operation  of  the  system,  prepare  two  lead  straps  by  cleaning 
with  “file  card”  or  shave  hook.  Fig.  23.  Place  the  two  straps  on  a sheet  of  iron  in  the  position 
desired.  Fuse  the  two  by  playing  the  flame  carefully  along  the  line  of  intersection.  During  this  pro- 
cess add  a little  lead  of  the  same  composition  as  the  strap.  See  Fig.  24.  Block  up  sides  of  strap  to 
prevent  running  away  of  molten  lead. 


Fig.  25-a. 


Copyright  1922,  B.  B.  Burling 
Bruce,  Milwaukee,  Publishers 


Loose  Leaf  Shop  Manual 
Burling  Vocational  Series 
Battery  Testing  and  Repair 


3.  Burn  in  a new  plate  where  one  has  been  removed.  This  is  done  by  cutting  a slot  with  a hack 
saw  in  the  plate  connecting  strap  the  width  of  the  conducting  lug  of  the  plate.  Figs.  25-a  and  b.  Clean 
thoroughly  and  wash  with  soda  water,  if  found  necessary,  before  burning. 

4.  Burn  a strap  with  alternating  current  low  voltage.  Fig.  28. 

5.  Burn  a strap  with  direct  current  low  voltage.  Figs.  29  a,  b,  and  c. 

6.  Set  up  a burning  rack  and  burn  on  new  plates.  Figs.  30a  and  b. 

7.  Solder  cable  to  terminal  lugs  (“tinning”  and  “sweating”). 


Questions 

1.  Compare  the  time  required  by  each  method  of  burning. 

2.  In  which  gas  line  should  the  water  valve  be  connected?  Why? 

3.  When  burning  on  a post  or  working  with  a flame  around  a battery,  why  should  the  vent 
plugs  be  removed? 

4.  Why  is  it  necessary  to  heat  to  melting  point  both  surfaces  to  be  welded  before  allowing 
molten  lead  to  fill  in? 

5.  Explain  in  detail  the  operations  of  soldering  a cable  to  a terminal  lug. 

6.  Why  are  terminals  lead  burnt  and  not  soldered? 

7.  Why  are  terminals  lead  burnt  and  not  bolted? 

Theory — “Lead  burning”  is  the  fusing  of  lead  without  the  aid  of  other  metals  which  melt  at  a 

lower  temperature.  Soldering  is  the  joining  of  two  metals  with  the  aid  of  a lead  alloy,  of  lower  melt- 

ing point  than  the  metals  being  soldered,  and  a cleaning  flux.  Burning  may  be  done  with  a heated 
carbon  point  or  with  a pencil  pointed  flame. 

Commercially  the  flame  is  produced  by  hydrogen-oxygen,  acetylene-oxygen  or  illuminating  gas- 
oxygen.  The  water  valve  “A”  in  Fig.  26  is  of  utmost  importance  because  a “back  flash”  would  be 
liable  to  cause  a disastrous  explosion. 


Copyright  1922,  B.  B.  Burling 
Bruce,  Milwaukee,  Publishers 


Loose  Leaf  Shop  Manual 
Burling  Vocational  Series 
Battery  Testing  and  Repair 


If  too  large  a flame  is  used,  the  entire  lead  is  likely  to  melt  and  run  away  unless  confined  in  a 
mold,  or  by  retaining  strips  of  carbon  or  iron  placed  on  the  sides  of  the  “work.”  All  heavy  work  such 
as  extending  posts,  connecting  bus  bars,  etc.,  can  be  done  with  a large  flame.  The  smaller  the  work 
the  smaller  the  flame. 

Fig.  27  shows  a typical  flame  with  the  hottest  portion  indicated.  Always  use  the  concentrated 
hot  point  except  where  a general  heat  is  desired. 

For  light  work  an  electric  hot  point  is  sometimes  used,  although  the  method  is  likely  to  prove  quite 
expensive  especially  where  the  energy  is  from  a low  voltage  battery.  Fig.  28  shows  the  most  econo- 
mical electrical  method  although  the  apparatus  shown  in  Fig.  29  is  good  for  an  emergency. 

In  any  method  it  is  of  utmost  importance  to  fuse  the  surface  of  the  work  before  building  the  post, 
lug,  strap,  etc.  Clean  with  shave  hook  as  shown  in  Fig.  30c.  Only  add  molten  material  from  the 
“burning  stick”  when  the  surface  to  receive  it  is  molten.  If  the  terminal  is  lead  coated  copper  do  not 
use  a shave  hook  for  cleaning,  but  use  soda  and  scratch  brush.  Never  use  a flux  in  burning. 

Soldering  is  seldom  resorted  to,  although  if  terminals  of  repaired  batteries  show  exposed  copper  or 
brass,  the  same  should  be  retinned  before  being  replaced. 


Fig.  30-c. 


Copyright  1922,  B.  B.  Burling 
Bruce,  Milwaukee,  Publishers 


Loose  Leaf  Shop  Manual 
Burling  Vocational  Series 
Battery  Testing  and  Repair 


Job  A-21— MAJOR  DEFECTS  AND  REPAIRS. 

Object — To  detect  causes  and  to  repair  a battery  when  the  source  of  trouble  is  in  the  plates. 

Apparatus — Battery  to  be  repaired,  lead  burning  outfit,  steamer,  battery  plate  press,  high  rate 
tester,  voltmeter  and  hydrometer. 

Method 

1.  Charge  the  battery  over  night. 

2.  Examine  each  cell  to  locate  source  of  trouble. 

3.  Continue  charge  another  day  if  it  is  thought  that  the  cells  would  “come  up.” 

4.  After  the  battery  is  charged  as  much  as  possible,  blow  out  gas  in  each  cell,  then  remove  straps 
and  covers  by  methods  already  known. 

5.  Remove  all  shorts  between  plates  and  replace  for  recharge,  if  necessary. 

6.  Separate  the  -)-  and  — groups  and  press  separately  in  the  press  to  straighten  buckled  posi- 
tives and  bulged  negatives.  Fig.  31. 


Fig.  31. 

7.  Reassemble  the  elements  with  new  separators. 

8.  Place  in  cells  with  new  electrolyte  of  1.300-1.310  gravity. 

9.  Place  on  charge  before  sealing  if  there  is  any  doubt  as  to  the  condition  of  the  plates. 

10.  If  battery  charges  up  properly  seal  with  asphaltum,  Figs.  32,  33  and  34.  The  flame  is  playea 
on  the  surface  to  make  the  sealing  more  perfect  on  the  jars  and  terminal  posts. 


Theory 

In  making  major  repairs  on  a battery,  it  is  to  be  remembered  that  the  positive  plate  is  the  weaker 
and  should  be  handled  with  great  care.  Should  the  plate  crack  in  being  straightened,  the  plate  and 


Copyright  1922,  B.  B.  Burling 
Bruce.  Milwaukee,  Publishers 


Loose  Leaf  Shop  Manual 
Burling  Vocational  Series 
Battery  Testing  and  Repair 


possibly  the  entire  group  should  be  discarded.  In  straightening  any  group  of  plates,  spacing  boards 
should  be  placed  between  the  plates.  The  negative  material  is  generally  soft  and  is  therefore  more 
easily  pressed  into  shape. 

Before  any  internal  work  is  done  on  a battery,  the  plates  should  be  reduced  to  as  good  a con- 
dition as  possible.  This  preliminary  charging  softens  the  active  material  and  makes  the  work  easier 
on  the  plates,  as  well  as  for  the  operator. 

Plates  which  have  once  been  buckled  will  warp  very  easily  again.  Replace  the  old  separators 
with  good  hard  wood  ones  and  increase  the  charging  rate  on  the  car  slightly,  because  a semi-charged 
battery  will  buckle  very  quickly.  Over-charging  raises  the  temperature  and  softens  the  active  material. 
Undercharging  hardens  the  material  and  buckles  the  positive  plates. 

In  most  service  stations  the  straightening  of  the  positive  plates  is  never  done.  Slightly  buckled 
plates  may  be  returned  to  service  but  never  those  badly  distorted. 


Copyright  1922.  B.  B.  Burling 
Bruce.  Milwaukee,  Publishers 


Loose  Leaf  Shop  Manual 
Burling  Vocational  Series 
Battery  Testing  and  Repair 


Job  A-22— INSTALLATION  OF  NEW  OR  OLD  BATTERY 
Object — To  know  the  points  to  be  taken  care  of,  especially  in  re-installing  a battery  after  repairs. 
Apparatus — A battery  which  has  been  repaired  and  an  auto  which  is  in  garage  or  repair  shop. 

Method 

1.  See  that  the  battery  is  located  where  it  is  accessible  for  testing  and  adding  water. 

2.  The  battery  compartment  should  be  ventilated  and  means  for  draining  should  an  accident 
occur  and  spill  the  battery. 

3.  The  battery  should  rest  on  cleats  which  allows  an  air  space  on  the  bottom. 

4.  See  that  hold  downs  grip  the  handles  firmly.  No  cleat  or  hold  down'strap  across  the  top  of 
the  battery  should  be  permitted. 

5.  The  compartment  should  be  free  from  oil,  water,  dirt,  or  tools  and  be  kept  dry  at  all  times. 

6.  Wash  out  box  with  soda  water,  if  the  installation  is  in  an  old  car. 

7.  Coat  the  terminals  with  vaseline  or  heavy  grease  after  the  terminal  connections  have  been 
made. 

8.  Readjust  the  charging  rate  in  accordance  with  the  conditions  found  inside  the  cells.  If  there 
was  found  considerable  shedding  of  active  material  from  the  positive  plates,  reduce  the  rate 
two  to  four  amperes.  If  there  was  a buckling  of  the  plates  and  the  active  material  hard,  increase 
the  rate  two  to  four  amperes.  Excessive  charging  is  just  as  bad  as  under  charging.  A battery 
has  to  undergo  such  a variety  of  treatments  that  it  is  impossible  to  give  detailed  instructions  on  rates 
of  charge.  Follow  instructions  given  on  the  battery. 

Questions 

1.  How  can  you  determine  when  a battery  is  placed  in  a car  in  the  right  position? 

2.  What  is  liable  to  happen  if  the  battery  is  not  rigidly  secured  in  position? 


Copyright  1922,  B.  B.  Burling 
Bruce,  Milwaukee,  Publishers 


Loose  Leaf  Shop  Manual 
Burling  Vocational  Series 
Battery  Testing  and  Repair 


Job  A-23— CARE  OF  A STORAGE  BATTERY. 

Object — To  review  much  of  the  material  which  has  previously  been  given  on  the  subject  in  this 
text  and  elsewhere  and  obtain  detailed  information  on  the  care  of  a lead  storage  battery. 

TO  BE  REMEMBERED 


Installation 

1.  Accessibility  of  battery. 

2.  Ventilation  of  compartment. 

3.  Battery  securely  fastened  in  place. 

4.  Compartment  free  from  foreign  material. 

5.  Neutralization  of  acid  with  soda. 

6.  Protection  of  terminals  with  heavy  oils  or  grease. 

7.  Terminal  lugs  securely  fastened  to  battery  terminals. 

8.  Proper  charging  rate. 

Bi-weekly  inspection 

1.  Pure  water  added  periodically  (two  weeks  or  less)  to  proper  height.  Never  add  acid. 

2.  Test  with  hydrometer.  Record  results.  Never  below  1.150  sp.  gr. 

3.  Temperature  test  at  the  end  of  normal  run. 

4.  Test  connections. 

5.  Neutralize  acid  with  soda.  Note  cause  of  sloppage  and  try  to  prevent  same. 

6.  Coat  terminals  with  vaseline  or  grease. 

Special  Instructions 

1.  Never  bring  lighted  match  or  torch  near  charging  battery. 

2.  Charge  with  direct  current  always. 

3.  Connect  (-)-)  positive  charging  wire  to  (-)-)  positive  terminal  of  battery. 

4.  Charge  should  always  be  continuous  unless  the  temperature  rises  above  105°  F. 

5.  Should  battery  show  internal  trouble  have  repaired  immediately. 

6.  Have  acid  equalized  in  the  fall  of  each  year  before  freezing  temperatures  injure  the 

battery. 


CAUSES  OF  BATTERY  FAILURE  WHILE  IN  SERVICE 

1.  Open  in  generator  circuits,  causing  ammeter  to  always  indicate  discharge. 

2.  Loose  connection  in  generator  circuit  or  slipping  belt  causing  the  ammeter  to  fluctuate  con- 
siderably, possibly  registering  discharge. 

3.  Short  circuit  in  battery  system. 

4.  Excessive  night  running  with  all  lights  on. 

5.  Cut-out  not  set  right  or  not  operating  properly. 

6.  Much  very  slow  driving  at  night. 

7.  Using  car  for  short  runs  where  battery  cannot  recover  from  the  loss  sustained  in  starting  the 
motor. 

8.  Corroded  terminals  (poor  contact). 

9.  Ignition  switch  left  “on”  when  not  using  car. 

10.  Internal  short  due  to  buckled  plates  or  sediment. 

11.  Impurities  in  the  battery  causing  “local  action”  or  “local  discharge.” 

Questions 

1.  How  often  should  inspection  be  made  in  winter? 

2.  How  often  should  inspection  be  made  in  summer? 

3.  When  should  water  be  added  in  winter? 

4.  How  much  water  should  be  added? 

5.  What  effect  would  the  wet  top  of  cells  have? 

6.  What  action  has  the  acid  on  the  terminals? 

7.  Which  terminal  is  corroded  most?  What  is  the  color  due  to  corrosion? 

8.  What  is  sulphation? 

9.  Which  group  of  plates  is  most  likely  to  become  sulphated? 

10.  How  is  sulphate  reduced? 

11.  What  are  causes  of  buckling? 

12.  What  effect  does  charging  have  on  sulphation? 


Copyright  1922,  B.  B.  Burling 
Bruce,  Milwaukee,  Publishers 


Loose  Leaf  Shop  Manual 
Burling  Vocational  Series 
Battery  Testing  and  Repair 


13.  What  is  the  cause  of  sediment  at  the  bottom  of  cells? 

14.  Should  no  distilled  water  be  available,  what  water  could  be  used? 

15.  Should  the  temperature  rise  above  105°  F when  charging  on  the  car,  what  does  it  indicate 
What  can  be  done  to  prevent  such  a condition? 

16.  Can  you  suggest  any  improvements  which  you  think  would  give  longer  life  or  greater  serv 
ice  to  the  storage  battery? 

17.  When  would  you  consider  it  necessary  to  replace  the  acid  in  a battery? 

18.  What  is  the  cause  of  grids  cracking? 

19.  What  is  the  cause  of  plates  growing? 

20.  What  is  the  cause  of  loss  of  active  materiel? 

21.  What  is  cause  of  negatives  becoming  “mossed”? 

22.  What  is  the  cause  of  negatives  becoming  swelled? 

23.  What  is  the  result  of  age  on  the  negative  plates? 


Copyright  1922,  B.  B.  Burling 
Bruce,  Milwaukee,  Publishers 


Loose  Leaf  Shop  Manual 
Burling  Vocational  Series 
Battery  Testing  and  Repair 


Job  A-24— TESTING  AND  REPAIR  EQUIPMENT,  SHOP  ARRANGEMENT,  ETC. 

Object — To  give  the  student  first-hand  information  on  shop  practice. 

Equipment 

Testing 

0-30  range  ammeter 
0-3-15  range  voltmeter 
Cadmium  test  terminals 
High  rate  discharge  tester 
Syringe  hydrometer 
Thermometer 

Hydrometer  syringe  for  adding  water  to  cells 
Jar  tester 

Suitable  battery  charging  outfit  with  proper  current  regulators. 

Repair 

Battery  steamer 
Battery  press 
Bench  vise 

Hydrogen-oxygen  lead  burning  outfit 

Carbon  arc  burning  outfit 

Floor  battery  vise 

Plate  burning  stand 

Single  gas  hot  plate 

Sealing  compound  heating  pot  (coffee  pot) 

Separator  cutter 
Sink 

Water  Still  if  local  water  is  not  suitable 
Work  bench  (lead  covered) 

Charging  bench 
Storage  rack 

Stock  bins  for  repair  parts 

Storage  tank  for  separators 

Mold  for  casting  lead  burning  bars 

Flat  trays  for  disassembled  battery  parts 

Non-corrosive  soldering  flux  for  terminal  soldering 

Hand  Tools 

Brace  and  bit  54”,  %” 

Wire  brush 

Coarse  file  10"-12"  Vixen 
Hack  saw 
Hammer  (ball) 

Bristle  brush 
Bellows 

Putty  knives  1"  wide 
Gas  pliers 
Flat  nose  tongs 
Paint  brush 

Large  end  cutting  pliers 

Scraper 

Wrenches 

Screw  driver 

Center  punch 

Coarse  back  saw  blades 

File  brush 

3/16",  Y\" , 54”,  V 2"  wood  chisels 
Gasoline  torch 

Supplies 

1 — Carboy  1.300  acid 
1 — Carboy  1.400  acid 


Copyright  1922,  B.  B.  Burling 
Bruce,  Milwaukee,  Publishers 


Loose  Leaf  Shop  Manual 
Burling  Vocational  Series 
Battery  Testing  and  Repair 


Sealing  compound 
Asphaltum  paint 
Washing  soda 

Method 

1.  Secure  from  catalogs  and  other  sources  the  cost  of  the  minimum  equipment,  tools  and  sup- 
plies listed. 

2.  Secure  for  personal  use  all  available  catalogs  and  bulletins  covering  the  necessary  apparatus. 

3.  Submit  a report  on  cost  and  also  a detailed  sketch  of  the  arrangement  of  shop  or  workroom 
which  would  secure  economy  of  time  and  labor. 

4.  Submit  a “Job  Ticket”  which  would  be  suitable  for  battery  service  work. 


Copyright  1922,  B.  B.  Burling 
Bruce,  Milwaukee,  Publishers 


Loose  Leaf  Shop  Manual 
Burling  Vocational  Series 
Battery  Testing  and  Repair 


Job  A-25— ELECTRIC  VEHICLE  OPERATION 

Object — To  know  how  the  peculiar  characteristics  of  a battery  effect  the  operation  of  a vehicle. 
Apparatus — An  electric  vehicle  (pleasure  or  commercial)  if  available. 

Method 

1.  Install  an  ampere  hour  meter  on  electric  vehicle. 

2.  Discharge  under  service  conditions  at  various  points  on  controller  and  note  total  mileage 
obtained  under  each  test. 

3.  Note  the  action  of  the  car  (speed)  when  nearing  the  end  of  run. 

4.  Plot  a curve  between  mileage  and  points  on  controller. 

Questions 

1.  If  there  were  no  ampere  hour  meter  on  the  car,  how  would  you  know  the  approximate  con- 
dition of  the  battery? 

2.  Is  there  any  real  danger  of  being  stalled  in  an  electric  vehicle  if  the  driver  is  familiar  with  the 
use  of  the  electric  car?  Why? 

3.  What  conditions  will  be  noticed  when  the  battery  is  approaching  discharge? 

4.  How  should  the  battery  compartment  be  cared  for  so  as  to  avoid  corrosion  of  metal  parts  and 
rotting  of  the  wood? 

5.  If  a car  becomes  stalled  and  additional  mileage  is  made  after  standing  a while,  what  would 
the  effect  be  upon  the  battery?  To  what  extent  would  you  consider  this  injurious  to  the  battery? 

6.  On  which  point  of  the  controller  can  the  greatest  mileage  be  obtained? 


Copyright  1922,  B.  B.  Burling 
Bruce.  Milwaukee.  Publishers 


Loose  Leaf  Shop  Manual 
Burling  Vocational  Series 
Battery  Testing  and  Repair 


Job  A-26— CHARGING  EQUIPMENT 

Object — To  compare  the  efficiencies  of  commercial  charging  units. 

Apparatus — Motor-generator,  mercury  vapor  rectifier,  magnetic  vibrator  rectifier,  “Tungar”  or 
heated  cathode  rectifier,  rotating  commutator  rectifier,  two  wattmeters,  or  other  suitable  testing  instru- 
ments and  a storage  battery. 

Method 

1.  Examine  each  piece  of  apparatus  carefully  noting  all  name  plate  information. 

2.  Obtain  catalogs  from  companies  manufacturing  charging  apparatus. 

3.  Set  up  each  charging  set  with  wattmeters  and  battery.  Calculate  the  efficiency  at  low  and 
high  rates  of  charge  and  discharge. 

Questions 

1.  Which  apparatus  seems  most  adaptable  for  a small  services  station?  Why? 

2.  Which  apparatus  seems  most  serviceable  for  a large  station  giving  night  and  day  service? 
Why? 

3.  Which  proved  to  be  the  most  efficient  for  single  battery  charging? 

4.  Would  the  efficiency  be  the  same  if  more  batteries  were  charged  at  one  time?  Explain  in 
detail. 

5.  Calculate  the  cost  of  charging  a 60  ah  6 v.  battery  for  24  hours  at  6 amp.  rate.  Use  the  effi- 
ciencies for  each  of  the  above  rectifiers  as  found  by  actual  test. 

6.  Determine  the  first  cost  of  the  various  charging  equipment  from  the  manufacturers. 

Theory 

Motor-Generator,  as  the  name  indicates,  is  a combination  of  a motor  and  a generator  belted  or 
connected  together  on  the  same  shaft.  The  average  efficiency  of  this  type  of  charging  is  lower  than 
some  other  types,  but  as  it  is  possible  to  get  such  a set  in  any  capacity  desired,  most  of  the  large 
service  stations  are  so  equipped.  Cost  of  upkeep  is  very  low. 

Mercury  Vapor  Rectifier  has  a high  efficiency,  although  the  upkeep  cost  in  bulb  replacement 
is  considerable.  This  type  of  rectifier  makes  use  of  the  complete  alternating  current  wave,  which  is 
rectified  at  the  voltage  desired. 

“Tungar”  or  Heated  Cathode  Rectifier  eliminates  much  of  the  cost  of  upkeep  of  the  Mercury 
Rectifier  and  operates  at  approximately  seventy-five  percent  efficiency  under  normal  load.  The  fact 
that  it  will  automatically  stop  and  start  when  the  alternating  current  is  interrupted  without  any  com- 
plicated relay  system,  has  won  for  itself  a place  in  small  service  stations,  where  there  is  no  night 
attendant.  Bulb  cost  about  lc  per  hour  of  service. 

Rotating  Commutator  Rectifiers  have  been  placed  on  the  market  and,  although  inclined  to  be  a 
little  noisy,  when  the  commutator  becomes  pitted,  can  be  adjusted  to  deliver  direct  rectified  current,  at 
a full  load  efficiency  of  about  80-83  per  cent.  Under  heavy  loads,  excessive  sparking  will  result  and 
cooling  fans  are  necessary. 

Vibrating  Magnetic  Rectifiers  are  used  to  a considerable  extent  for  charging  one  or  two  batteries 
because  of  the  low  first  cost  and  upkeep.  The  efficiency  is  also  high.  For  service  station  work,  how- 
ever, its  use  is  very  limited. 


Copyright  1922,  B.  B.  Burling 
Bruce,  Milwaukee,  Publishers 


